Instructions for Building Studio Printing Surfaces
Overview
This family of platen designs describes ways of making screen printing platens with good characteristics for working with paper and other flat media. The platens are durable and low-cost, and can be built in several hours in the shop: some designs can be built in 2-3 hours and cost less than $30 in materials, and others in around 10 and cost $60. The construction techniques and materials are flexible, allowing a studio to design in cost, durability, and construction time.
These platens are an alternative to printing with tempered glass panels or laminate surfaces found in some studios; they match or improve on their consistency and durability, and add facilities for paper placement and registration, offset consistency, and screen registration.
This article is organized around:
- main forms: the platen types best supported in these designs: what can be easily built with existing resources, and an overview of their options
- elements: a discussion of different parts of the designs, their suitability, and how they relate to each other
- instructions: step-by-step instructions for each form, and a few common and useful recipes
- resources: design files, and sources for materials and services
Builders can read the main forms and elements sections to inform choices about what to build, or pick one of the design recipes included at the top of each platen type’s instructions. The instructions section has a general, step-by-step reference on how to build each platen type. The resource section optionally supplements the design and build process, with much of the digital design and material sourcing already done. Altogether, these notes and resources can also inform designs for different platens.
Main Forms
Plywood Platen
The plywood platen consists of a plywood panel with a printing surface laid on top. Hinge clamps are fastened onto the plywood, forming a complete printing unit that can be used on a table.
Either plastic or glass can be a printing surface. A printing grid can be added in between the plywood and the printing surface, making visual alignment straightforward. The platen can be installed on a table, or used when placed down—then moved and stored away.
Surface Platen
A plastic or tempered glass panel provides a printing surface that can be added to a hinge clamp setup. The panel can rest on its own, or be fastened to the table. A printing grid can be added underneath the panel to aid with paper registration.
Elements
Hinge Clamp
All designs are based around the speedball hinge clamp. This clamp is widely available, and widely in use. It is cheap, durable, clamps well onto screens, and is able to mount onto any surface with bolts or screws. Other clamps can be used, but do not have design resources provided.
On its own, the hinge clamp has a built-in offset of 1/4” when mounted onto a printing surface. This is too high for printing, where an offset of 1/8” or less is preferred. This built-in offset makes for difficult printing, or reduces the area of the screen that can be used.
One common feature in both designs is to reduce this built-in offset by lowering the clamp base, relative to the print surface. For both plywood platen and surface platen designs, the added panel raises the printing surface relative to the jaws. For plywood platen designs, the clamp base can also be lowered into a routed pocket.
When printing on thicker materials, the screen offset can be adjusted to match, using offset shims that slip onto the hinge clamp base and other shims taped or clamped to the screen frame. A riser can further boost the clamp up past the clamp’s maximum offset height. See the offset height section for more information.
Printing Surface
Many materials can be used as a printing surface. The primary characteristics are that the material be flat, and durable enough for printing and cleaning. When used with a registration grid, the printing surface must be transparent and scratch-resistant.
Sheet Glass
Sheet glass, particularly in the form of storm window glass, is durable enough for most uses: it can be cut by hand, is waterproof and non-reactive, and relatively scratch-resistant. It is also easily sourced and exceptionally cheap. It is not strong enough on its own, and needs support underneath and around its edges to prevent breakage or injury:
- In the plywood platen, the plywood supports the glass underneath, and tabs on the platen’s side retain the glass and protect its edges. In this design, the risk of breakage and difficulty of retaining the glass when flipped means the plywood platen should be installed on a table, and not stored or moved.
- In the surface platen, thin sheet glass is not recommended as a printing surface.
Tempered Glass
Tempered glass panels can be used. It is stronger than sheet glass, and does not need as much support underneath: a 1/4” panel can span a few feet at printing pressures, though an 1/8” panel should be backed. It is more scratch resistant, but expensive and unworkable by hand—it must be made to order. When broken, it forms smaller, square fragments, and so is less dangerous. In the plywood platen, the construction is the same as sheet glass. It can be used in the surface platen, if the panel is thick enough (about 1/4”) and its edges rounded over.
Plastic Sheets
Plastic sheets, such as acrylic, polycarbonate, and PET-G, can be used. These are less scratch resistant, but are easier to modify and mount. In the plywood platen, a panel can be drilled and screwed into a plywood panel; the platen can then be flipped, moved, and stored with no risk of the panel breaking or falling off. Plastic panels are ideal for the surface platen design.
Offset Height and Adjustment
Ideally, screens are parallel and offset from the printing material by 1/8” or less, depending on the printing situation (frame type, tension, ink, material, etc.). To support this setup, these designs have plastic shims that raise the screen to a chosen, and adjust it to parallel. One pair of shims mounts on the hinge clamp jaws, and another pair is taped or clamped on the opposite end of the frame.
The hinge clamp and frame end shims may have different thicknesses for a setup. As background, there are two offsets: the material offset is the distance between frame and material; the surface offset is the distance between frame and printing surface—this is the material offset plus the material thickness. In addition, every platen design places the hinge clamp at some built-in offset: this is the installed offset. On its own, the hinge clamp has a built-in, installed offset of 1/4” from the surface it is mounted on. Laying down a printing surface in front of the clamp reduces this offset. For example, with a surface platen, a 1/8” panel laid down on a table has an installed 1/8” offset: 1/4” of the clamp jaw to start, minus the 1/8” of the panel. Lowering the clamp into a routed pocket, an option with the plywood platen, reduces this offset further.
For finding the frame shim thickness, the material or surface offset may be used. If the frame end rests on the material, the shim is the material offset. Otherwise, if the frame end rests on the printing surface, or if the material has no significant thickness, the shim is the surface offset.
For finding the hinge clamp shim thickness, the shim is the surface offset, minus the installed offset.
Offset shims are provided as reconfigurable models. These can be modified easily for any platen design, and produced on a consumer-grade 3D printer locally or ordered from an online service. The designs can be accessed and customized in the design files section. Online services are listed in the services section.
Registration Grid
A registration grid provides a way to align paper by hand and eye. It can be added underneath any transparent printing surface.
A grid can be printed on paper using a large-format printer and glued in place, with either platen design. It can also be scribed into a plywood platen’s base panel using a laser cutter; this technique creates a more durable grid, but requires more time and skill. A thinner printing surface makes for better alignment, as a thicker surface increases the possible skew between the paper and the registration lines.
Some formats have a centerline “stem” that extends to the bottom end of the platen, between the hinge clamps. Use the stem-variant only if the stem can be waterproofed: with clear-coat spraypaint over a paper grid, with a plastic printing surface that extends to the bottom end, or on its own with a scribed grid.
Grids for common frame sizes and orientations are available in the printing grid section.
Backing and Mounting
Some platens need to be installed onto a table. These might not be heavy enough to sit on their own, need to be pulled into flat, or have fragile glass elements.
Plywood platens can be fastened to a the table in a few ways. Bolts or screws can be added to the panel’s corners, underneath the printing surface. If the printing surface is plastic, the fastener can run through the plywood and the printing surface, holding both in place. For scenarios where visible heads are unwelcome, threaded inserts allow bolting from the bottom, and screws from underneath can work in the right length. If using a printed paper registration grid, this can be glued down over any heads on the panel.
Surface platens, if made of plastic, can be drilled in the corners and fastened into the table.
Alternatively, for both platen types, blocks nailed around the panel outline can hold the platen in place.
Paper Registration
In addition to existing registration methods, several lengths and widths of L-brackets are included with these designs. This technique is used widely in letterpress printing, and support rapid paper registration against an edge and corner. While efficient, the bracket prevents printing on thin materials within a marginal distance from the bracket, as the screen cannot lower to the medium.
They can be cut out of thin plastic, locally or from an online service; PETG available from ponoko at .04” (~1/32”) is particularly well-suited. Acrylic is increasingly brittle below 1/8”. The models are available in the design files section, and services for fabricating them are listed in the materials services section.
Screen Registration
These designs include resources for adjusting the screen’s horizontal placement above the printing surface. These adjustments are referred to as the skew (left-to-right angle) and inset (front-to-back placement).
This adjustment is added with a bolt to each hinge clamp; a hole is drilled and tapped into its back wall. The bolt drives horizontally against the screen frame side, pushing it in and out of the clamp. With one on each clamp, adjusting one changes the skew and adjusting both changes the inset. Using a 10-32 bolt (just fits) provides 7-8 thousandths of adjustment per quarter-turn.
Instructions
Building a Plywood Platen
The plywood platen has a plywood panel at its base, a printing surface on top, optional tabs to hold the printing surface in, and hinge clamps bolted onto the plywood. A printing grid can go under the printing surface.
It is built by cutting the plywood base and printing surface to size; creating a pocket for the hinge clamp to sit in; adding a printing grid to the plywood; adding side tabs to hold the printing surface, or screwing it into the plywood; adding bolts or screws to fasten the hinge clamp; and adding any mounting hardware to install on a table.
Offset shims and risers can be used with the hinge clamps and screen; for more discussion and resources, see the Offset Height and Adjustment section, and the design file resources.
Parts List
| Part Name | Description |
|---|---|
| Plywood Panel | Base panel of the platen, made from 1/2” or 3/4”-thick plywood. 3/4” is preferred, if flat. |
| Printing Surface | Sheet glass, tempered glass, or plastic panel. Any thickness up to 1/4” thick; around 1/8” works best. |
| Printing Grid (Optional) | Grid used for aligning paper. Printed paper from a large-format printer, or scribed grid made with white/black spraypaint. |
| Side Tabs (Optional) | Tabs for holding the printing surface within the plywood panel. 1/8”-thick plywood or solid wood. Tabs are needed for glass printing surfaces, and optional for plastic panels. |
| Top Tab (Optional) | Tab for holding printing panel forward from the hinge clamps. Should be at least as thick as the printing surface, and 1/4” - 3/8” wide. Needed for glass printing surfaces. |
| Tab Fasteners | Nails or screws for holding the side and top tabs in. 1/2”-5/8” long works well; these can be longer for the side tabs, and no longer than the plywood thickness for the top tab. |
| Hinge Clamps | Hinge clamps from Speedball. |
| Hinge Clamp Mounting Hardware | 10-32 bolts, nuts, and washers, or #8-#10 wood screws. Prefer head with V-shape into the body, such as flat head. |
| Platen Mounting Hardware (Optional) | 10-32 threaded inserts and bolts/washers, or #10 wood screws, for attaching the platen to the table. Alternatively, 10-32 bolt-receiver threaded inserts. |
Dimensions and Calculating Them
The table below lists all dimensions needed for building the platen, and how to calculate them.
A pdf version of this table can be printed out and filled in. Alternatively, a spreadsheet with the formulas already in place is available: copy or download this, then fill the inputs in the left column. The derived calculations will appear in the right column.
| Dimension Name | Definition and Instructions for Figuring | Notes |
|---|---|---|
| Plywood Panel Length | The length of the plywood panel. Take the long dimension of the largest screen, and add 4”; the hinge clamps mount in this 4”. |
The panel can be slightly smaller to allow panels from a single sheet of plywood. A full plywood sheet of 4’ x 8’ can be cut into two 23-7/8” wide panels. |
| Plywood Panel Width | The width of the plywood panel. Pick between the long and short dimension of the largest screen. Using the long dimension will allow printing with the screen either way, and leaves room for paper margins. Any dimension between these two is also useable. |
Same as above, with undersizing the width to allow cuts. |
| Printing Surface Length | The length of the printing surface pane: for glass, use the long dimension of the largest screen. For plastic, pick can be as long as its supporting panel, with cutouts for the hinge clamps. For glass, subtract 1/16” to 1/8”. |
Extra room with glass is left for caulking material. |
| Printing Surface Width | The width of the printing surface panel. Re-use the plywood panel width, or subtract 1/16” to 1/8” for glass. |
|
| Printing Grid Length | The grid box’s printed length. Take the printing surface length, and subtract 1 inch. |
If printed on paper, the paper must be the printing surface length. |
| Printing Grid Width | The grid box’s printed width. Take the printing surface width, and subtract 1 or 2 inches to the nearest even number. |
If printed on paper, the paper must be the printing surface width. |
| Hinge Clamp Router Pocket | The depth of the hinge clamp’s router pocket. To achieve 0” offset, take the thickness of the printing surface, and subtract this from 1/4”. To achieve 1/8” offset, take the thickness of the printing surface, and subtract this from 1/8”. |
|
| Hinge Clamp Installed Offset | The offset of the hinge clamp, when installed. This parameter is not specified, but is the result of the printing surface thickness and the hinge clamp router pocket depth. This can be measured, or calculated by subtracting (1/4” - the printing surface thickness - the pocket depth). |
|
| Hinge Clamp Mounting Fastener Length | The shaft length of the bolts or screws that hold the hinge clamp into the plywood panel. This length is around the plywood thickness, minus any router pocket depth. |
|
| Side Tab Pieces | The length and width of each tab piece, for the ends and sides. Make two end tabs that are a little more than the plywood panel width, and two side that are the plywood panel length. The width of the tabs is a little more (1/32”) than the plywood thickness plus the printing surface thickness. |
When installing these, cut the width-running pieces to fit. |
| Top Tab Piece | The length and thickness of the top tab piece. The length is the width of the plywood panel. The thickness is either the thickness of the printing surface, or any thickness up to 1/8” greater than the thickness of the printing surface. For this second option, which is easier to find in stock thicknesses (like the 1/8” used in the side tabs), the installed clamp offset must be 1/8”, not 0”. |
Design Recipes
Example: Simple Sheet Glass Platen
This platen is designed around a 20x24 screen, so that this screen can be printed in either orientation. The sheet glass is 1/8” thick, and the platen has an installed offset of 1/8”.
Following the dimensions chart:
- for the 20x24 screen, the larger dimension is 24”. The plywood backer is then 24” wide by 28” long, and is 3/4” thick.
- the printing surface is 23-7/8” wide by 23-7/8” long, as a little room is left for caulking the glass. The printing is printed on paper, and glued onto the plywood surface; the grid box is 22” wide by 23” long, with number labels that extend a little further. The printing grid design for this size is available in the design files section.
- the printing surface is 1/8” thick; the router pocket is excluded, so the hinge clamp has an installed 1/8” offset (1/4” built-in clamp height, minus 1/8” of the printing surface).
- the side tabs are 1/8” thick, with end tabs a little more than 24-1/4” long, and side tabs that are 28” long. The top tab is 1/8” thick to match the 1/8” sheet glass, and is 24” long.
Example: Complex Sheet Glass Platen
This platen is similar to the platen above, but uses a 3/32” piece of sheet glass and features a 0” installed offset; the router pocket must be added to achieve this.
Dimensionally, only the printing surface thickness and top tab differ from above:
- the printing surface is 3/32” thick, and paired with a 5/32” deep router pocket, lowering the hinge clamp to 0” offset (3/32” from the printing surface and 5/32” from the pocket add to 1/4”, the built-in height of the hinge clamp).
- the side tabs are 1/8” thick, with end tabs around 24-1/4” long, and side tabs that are 28” long. The top tab is 3/32” thick to match the 3/32” sheet glass, and is 24” long.
Example: Simple Acrylic and Plywood Platen
This is a simple platen for a 20x24 frame.
Take a 20”x24” piece of 1/8”-thick acrylic, and align one end with a 20”x28” piece of 1/4” to 3/4” piece of plywood. Drill 1/4” holes in each corner, set in 1/2” from each end. Use #10 round head or countersunk flat head wood screws that are the same thickness as the plywood to fasten the acrylic to the plywood. Do the same for the hinge clamp mounting holes.
Step-By-Step Instructions: All Features
Cutting the Plywood Backer
Cut the plywood to length and width on a tablesaw or panel saw. Accuracy is important with tempered glass printing surfaces; it is sometimes best to have the glass already.
The resources section discusss finding tablesaws and alternatives.
Cutting the Printing Surface
Sheet Glass
Use a rolling glass cutter with a straight edge to cut the sheet glass.
First, mark the cut with a marker. Place the plywood on top of the glass, and align a corner and its two adjacent edges. Mark the opposite corner and its adjacent edges. Note and mark the aligned corner and orientation (which side up) on the plywood and glass; the glass should be installed in this same orientation.
Using a straight-edge, cut about 1/16” back from these lines. Cut and snap one end first. If the margin is healthy, snap by hand. Otherwise, set a straight brace on the other side of the cut, and snap.
Tempered Glass
Tempered glass must be ordered, and will arrive cut to size. If the plywood or glass are inaccurate, order the glass first and transfer the outlines onto the plywood.
Plastic/Acrylic
Most plastic can be cut on the tablesaw, or with a scoring tool.
As with the sheet glass, transfer the plywood outlines onto the plastic. Cut to the line if no side tabs are being used, or set back a little.
Sometimes the plastic can be cut with the same settings as the original plywood, to match exactly.
Routing Out Hinge Clamp Pockets
This operation requires a router with a bushing or template bearing, and knowledge in router use. If this is not available, instead use a 1/8” to 1/4” printing surface. This will bring the installed offset of the hinge clamp under 1/8”. — Routing out clamp pockets allows the hinge clamp to print at a lower offset.
Make a template for routing out the pockets. The pockets start 3/8 to 1/2” from the edge, with hinge clamp center lines 10-12” apart. The template can be made in plywood, by tracing the clamp outlines in pencil, and drilling, coping, and sanding the outline smooth. The template must include the jaw. Leave extra room for added diameter from any bushings, and room for 1/16” in variations from the hinge clamp castings. A digital template is available for printing and tracing, or cutting out on a laser cutter.
The template must be wide enough to support the router base. Either add supports around, or make the template large enough; on the underside, register against the end of the panel with nailed-in blocks, and support the template end with blocks as thick as the panel.
Setting the depth of the router can be difficult. Have a clamp and a sample of the printing surface on hand to check. Routing deeper is fine, as the clamps can be shimmed up to the desired offset with metal strips. Cut these to the depth of the mount base, and place to the left and right of its mount holes.
Drilling Hinge Mounting Holes
Transfer the hinge clamp mount holes onto the plywood, and drill through the panel.
If using #10 bolts, drill a 1/4” hole through. Support the wood underneath the drill holes. When finished, flip the panel, and drill a counterbore hole wide and deep enough to just bury the nut and washer. Guide this drilling with clamped guide block, made by drilling the counterbore size through.
If using screws, drill a small hole for the screws, using a bit no wider than the screw’s core without the threads.
Adding Registration Grids: Options
Grids are available in the printing grids section.
Paper Grid
With the paper printout in hand, two tasks remain: registering the grid onto the platen, and gluing it in place.
Determine the paper’s placement on the plywood backer. If oversize, the paper can be taped in place along one edge and un-hinged. Alternatively, the paper can be marked and cut to fit the backer, then aligned by butting two adjacent edges against an L-shaped guide.
Apply glue, then lower the paper onto the backer from one side, smoothing outwards. Trim any excess by flipping the backer over and cutting along the edge.
Scribed Grid
A grid can be scribed onto the surface using a laser cutter. This is done by painting the plywood panel with the grid’s background color, masking out the surface with tape, scribing the grid pattern through the tape mask, painting into the scribe relief, then peeling the mask.
Begin by building up two or three light coats of rolled or sprayed paint on the primed wood panel. Lightly sand between coats using wet sandpaper, a little water, and a sanding block. After sanding, remove any excess paint with several rounds of wiping with a wet cloth.
Once the background color is dry and ready, mask the entire surface with strips of blue tape or another mask.
Pick between two design file types for the laser cutter; neither is ideal. One uses vector cutting for all lines, where bold lines are built up from multiple, overlapping scribes. The second file uses raster cutting. The vector-based file runs in about half the time, but is less resilient against variations from machine to machine. The raster file is more consistent, but may need x- and y-axis rastering support to shorten the job’s time. For an 24”x28” platen design, the run time is 1 hour with multi-axis rastering; without, it is 5 hours. The vector file runs in 1/2 an hour. For either file type, registering the panel is machine-dependent. The panel outline is included in the full design files, and can locate the panel edge.
Once the laser cutting is complete, paint the second color into the scribe. Apply one thin coat of matte clear coat first, and wait 24 hours for it to dry; this will seal the grain of the plywood from the grid paint, which can seep. Apply the grid paint; use two thin coats, again separated by a few hours or a day.
Peel off the stencil. Wait at least a day for the paint to dry, but do not wait more than a few days. Use only your fingernails; anything else will scuff the background color.
Clean up the surface with a magic eraser, made slightly damp. Wetting and wringing it will extend its life.
No Grid
If a grid isn’t desired, the surface can be painted a single color.
Side and Top Tab Sizing, Cutting, and Installing
For platens designed with glass, tabs wrap the platen sides to protect the glass edges and hold the panel in place. For any printing surface, side tabs can protect the plywood edges (porous) and printing grid from water and ink.
Use a tablesaw or bandsaw to cut the side tabs to the desired width; size them a little wider (1/32-1/16”) than the plywood and printing surface together.
Install the side tabs first; apply glue along the side of the plywood, and press the tab roughly into place; adjust so the ends align with the panel ends, and the tab’s top is slightly above the printing surface. Clamp one end, drill a pilot hole for a nail or screw, and fasten it in place. Move down the tab in the same way.
Cut the end tabs to fit against the side tabs, and install in the same way. For the top tab, cut to fit within the side tab, and glue and fasten down into the plywood.
Throughout, a damp cloth should be used to remove excess glue squeezed onto the platen surface. If this dries, it can raise the printing surface up, making it easier to damage.
Platen Mounting
Bolting Down
A platen can be fastened down into the table. For any designs using glass, the platen should be bolted into a table. Otherwise, the platen may be able to sit on its own, or stored away. For all designs, 10-32 bolts or #10 screws work well.
For glass printing surfaces, the fastener must be installed under the printing surface, through the plywood panel. Drill mount holes in each corner, countersink them, and use a flat-head fastener. The head must be below the plywood surface.
For plastic surfaces, the fastener can be installed through the plastic and plywood; this will hold them together. Drill mount holes in each corner; if the corners will interfere with the frame or printing, countersink the holes.
Outline Blocks
A platen can be held with wood blocks around it. Using eight blocks, two around each corner, fasten these into the table around the platen.
Threaded Inserts
A platen can be mounted from below using threaded inserts; an insert has a wood screw on the outside, which will screw into the panel bottom. The insert’s inside acts like a nut, and can accept a bolt. Inserts have no bolts not visible from the surface, but more time to use.
Place one threaded insert in each corner, and one in the center. If the panel is still warped away from the table, add one insert into the middle of each edge. Otherwise, if the table is not flat and the panel warps in either direction, correct with shims.
Drill a hole for an insert with a drill about the diameter of the insert core, without the threads. Mark the depth on the drill bit with marker or wrapped tape to prevent drilling through the other surface.
Screw the inserts in, then transfer the marks to the table. Do this by tracing onto a paper sheet, poking the centers through, then transferring the marks onto the table. Drill through, then bolt into the platen from the other side.
Some threaded insert products are listed in the resources section.
Building a Surface Platen
Parts List
A surface platen is simple, and consists of a printing surface and an optional printing grid.
| Part Name | Description | Dimension |
|---|---|---|
| Printing Surface | Printing surface of the platen, made from 1/8” to 1/4” plastic or tempered glass. | The printing panel can be the dimensions of the largest frame used, or the long dimension of the frame as a square. |
| Printing Grid | Grid used for aligning paper. Printed paper from a large-format printer. | The grid box is the length of the panel, minus 1 or 2 inches, and the width of the panel, minus 1 or 2 inches—whichever is an even number. |
| Screws (Optional) | Hold the printing surface into the table | At least 1/2”, but no more than the printing surface and table’s combined thickness |
Offset shims and risers can be used with the hinge clamps and screen; for more discussion, see the elements section discussion. The design files for these parts are available in the resources section.
Cutting a Printing Panel
Acrylic panels can be cut by hand, using a scoring tool and a ruler. If the acrylic is thin, use a separate panel to brace against the score line. Acrylic and other plastic panels can also be cut on the tablesaw.
After cutting, round the edges and corners with a file or sandpaper.
Mounting a Printing Panel
The panel can sit on its own, and taped in place for complex setups. It can be held tight in a few ways.
Corner Fasteners
A panel can be mounted into a table with screws in each corner. Drill a hole about 1/2” in from each end, and countersink them to hide a flat-head fastener. A round head can also be used, if printing is well within the margins.
Outline Blocks
Wood blocks nailed onto the table can hold a printing panel in place. Put one at each side of a corner.
Adding the Printing Grid
The printing grid can be laid on the table under the panel. If gluing, slowly lower from one end and push outwards. The grid can also be glued to the underside of the printing panel. Trim to within the printing panel.
Add a bead of silicon caulking around the edge of the panel to prevent water and ink from reaching the grid.
Other Instructions
Modifying Hinge Clamps
With a vice, mount and hold the hinge clamp face down, with one end of the back wall extending past the end of the vice jaws. Before drilling, check positioning with a 10-32 body hole drill (#7-#9). Drill a 10-32 tap hole (#21) as low down as possible, and tap to 10-32.
If no vice/press is available, carefully drill by hand. Punch the center of the hole to make a divot for the drill. Drill straight against a braced clamp.
Resources
Design Files
Printing Grids
Printing grid are available as PDF files, and designed for use with common screen sizes and orientations.
These are available for the screen sizes 12x16, 20x24, and 25x36; some formats support the frame clamped in either orientation, and others support only the short edge clamped.
Note that the PDF files are layed out so hinge clamps are placed at the bottom; the printer is standing on one side, or the opposite end. While the design reads as upside-down, this layout–when placed on the platen–maintains the constrained edge towards the bottom: against either the hinge clamps (no stem), or the platen edge (stem).
| Screen Size | Printing Surface Size | Grid Box Size | Platen Design | File Link |
| 12x16 | 12x16 | 10x15 | Designed for a 12x16 printing surface, where the 16” side faces the clamps. | 12x16_no_stem.pdf, 12x16_stem.pdf |
| 12x16 | 16x16 | 14x15 | Designed for a 16x16 printing surface, where a 12x16 frame can be used in either orientation. | 16x16_no_stem.pdf, 16x16_stem.pdf |
| 20x24 | 20x24 | 18x23 | Designed for a 20x24 printing surface, where the 20” frame side faces the clamps. | 20x24_no_stem.pdf, 20x24_stem.pdf |
| 20x24 | 24x24 | 22x23 | Designed for a 24x24 printing surface, where the frame can be used in either orientation. | 24x24_no_stem.pdf, 24x24_stem.pdf |
| 25x36 | 25x36 | 24x35 | Designed for a 25x36 printing surface, where the 25” frame side faces the clamps. | 25x36_no_stem.pdf, 25x36_stem.pdf |
The full designs are also available in their original svg format. This variant is the source for all other designs, and is more useful for some purposes: it represents each tick with a path and thickness–instead of with a rectangle, and holds each tick in a logical layer and color-code. It has a boundary edge around the panel. This file type is easier to work with for modifications, and for laser cutting.
| Screen Size | Printing Surface Size | Grid Box Size | File Link |
| 12x16 | 12x16 | 10x15 | full_12x16.svg |
| 12x16 | 16x16 | 14x15 | full_16x16.svg |
| 20x24 | 20x24 | 18x23 | full_20x24.svg |
| 20x24 | 24x24 | 22x23 | full_24x24.svg |
| 25x36 | 12x16 | 24x35 | full_25x36.svg |
Configuring CAD Files
The CAD files provided through onshape can be reconfigured online to match a specific platen design. A configuration can be calculated to match a platen design, then specified to the onshape design; this configuration will change the design, and generate a new part for downloading.
To reconfigure a model, visit a design’s onshape link. As an example, the model for the combined hinge clamp and frame shims looks like this:
In the top left, under the “Configurations” heading, are the options that can be modified in this model. Some settings are programmed as numbers, and others selected from a drop-down menu:
In this model, the surface offset (“Offset”) can be entered, along with the installed offset for a specific platen. The width and length for the frame shim can also be changed. The model will change to reflect updates to these configurations.
Download the updated model for each part by right-clicking on its entry in the “Parts” table, in the lower left corner:
A series of options for model type and units will appear. Most 3D printers use STL files, while most laser cutters use a DXF file; the units depend on the processing program using the model, but mm, cm, and inches are commonly accepted units:
Offset Shim Models
Offset shims are added to the hinge clamps and the frame to raise the frame to parallel and offset from the printing material. As discussed in the elements section, different platens can have different offset requirements. The clamp shim thickness is the surface offset, minus the installed offset. The frame shim thickness is the material or surface offset, depending on the situation.
Both offset shims are provided as 3D models that can be reconfigured to match each platen. These configured models can then be produced on 3D printers.
Models for different scenarios are below:
Printing Surface Model for Both Shims
This model specifies the hinge clamp and frame offset shims together, with a small rectangle mocking out the print surface. The actual hinge clamp jaw ends right below the offset.
To configure this model for a platen, enter the surface offset, then the installed offset of the platen. The installed offset should never exceed the surface offset. This will update the hinge clamp shim. For the frame shim, enter the offset, and use the shim as a surface or material shim.
Hinge Clamp Offset Shim
The hinge clamp offset shim is available as its own model. This model can be configured to a variable offset, and updated to have a smooth top, instead of divots. Smooth shims stack better than ones with divots, and a few well-chosen sizes of these (1/16”, 1/8”, 1/4”) can fit many printing scenarios.
Frame Offset Shims
The frame offset shim is also available as its own model; the width, length, and desired offset can be configured.
Hinge Clamp Template Outline
The hinge clamp outline is available here.
In the model, the offset around the outline can be configured; a default of 3/16” is specified.
Hinge Clamp Router Pocket Template
The router pocket template is available here.
The model can be reconfigured, as with the offset shim models. The offset around the outline can be configured (3/16” is specified), along with the spacing between the hinge clamp centers, and the extra room on three sides around the outlines.
Clamp Risers
The clamp riser model is available here. Risers go underneath the hinge clamp, to raise the jaws above the maximum possible shim height of ~1/2”. The model can be modified for any height.
Paper Registration Brackets
L-brackets for paper registration are available here.
Sizes for this model are specified by the length, in inches, of the registration edge. These can be selected from the “Edge Length” drop-down. Sensible changes to the remaining L-dimensions are made with each change. If these dimension pairings are insufficient, a free-form model with all four dimensions as variables is available here.
To export the 2D outline of the bracket, right-click on the bracket’s top face and select “Export as DXF/DWG”:
Materials Sources and Services
Hinge Clamps
Speedball Hinge Clamps can be found in many art stores, and are also available online at blick and amazon:
Threaded Inserts
Threaded inserts screw into the bottom of the plywood platen to mount it from below. Some threaded inserts need special screw drivers to thread into the wood.
As with any screw, drill a hole about the diameter of the core screw, without the threads; err on a larger diameter. The depth should be at least 1/8” than the plywood; if using a brad point drill, the tip will exceed past the cleared bottom.
These are a few product options, with differing heights and insertion methods:
| Insert Height | Plywood Size | Insertion Type | Link |
| 1/2” | 3/4” | Flathead | Page |
| 1/2” | 3/4” | Flathead | Page |
| 13mm (~1/2”) | 3/4” | Allen Wrench | Page |
| 20mm (~3/4”) | 7/8”+ | Allen Wrench | Page |
Printing Grid Services
Many local printers have large format printers that can print the printing grid onto a wide roll of paper.
Fedex is one common option; the grid designs can be printed with their architectural printing.
For online ordering, the #20, #24, and #32 bond paper options from blueprints printing are an affordable, but untested option.
Plywood Platen: Plywood Panel
Any flat, void-free board can be used for the plywood panel. Common boards that are suitable are baltic birch, MDF, and MDO. (MDF needs side tabs to protect from water.) These are easily found at hardware stores or Home Depot.
This table lists a few choices available at Home Depot:
| Part Name | Cost | Note | Sources |
|---|---|---|---|
| 1/2” MDF Board | 13 | Panel is 24”x48”, and will need to be cut | Page |
| 3/4” MDF Board | 13 | Panel is 24”x48”, and will need to be cut. | Page |
| 1/2” Birch Plywood | 22 | Page | |
| 3/4” Maple Plywood | ~26 | Page |
Plywood Platen: Side and Top Tabs
1/8” thick plywood works well for tabs, and is available at many hardware stores. One home depot listing is here.
Plywood Platen: Printing Surface
For plywood platens, printing surfaces can be up to 1/4” thick, though thinner allows for easier alignment with a printing grid. This chart has a range of plastic and sheet glass sources about 3/32” thick.
| Screen Size | Part Name | Cost | Note | Sources |
| 12 x 16 | ||||
| Printing Surface — Sheet Glass at 3/32” thick | ~5 | Page | ||
| Printing Surface — Sheet Glass at 1/8” thick | ~5 | Preferred for plywood platens without router pockets. | Page | |
| Printing Surface — Acrylic at 1/16” | ~15 | Panel is 12x24, and needs to be cut. | Page | |
| 20 x 24 | ||||
| Printing Surface — Sheet Glass at 3/32” thick | ~13 | Panel is 24x30 | Page | |
| Printing Surface — Sheet Glass at 1/8” thick | 15 | Panel is 24x36 initially. Preferred for plywood platens without router pockets. |
Page | |
| Printing Surface — Acrylic at 1/16” | 27 | Page | ||
| 25 x 36 | ||||
| Printing Surface — Sheet Glass at 3/32” | ~18 | Panel is 30x36 | Page | |
| Printing Surface — Acrylic at 3/32” | ~32 | Panel is 30x36 | Page |
Surface Panel Platen: Printing Surface
For surface platens, printing surfaces range from 1/8” to 1/4” thick. This table has a range of 1/8” plastic panels.
| Screen Size | Panel Source | Cost | Note | Link |
|---|---|---|---|---|
| 12 x 16 | Home Depot | ~17 | Panel is 12 x 24; needs to be cut to size. | Page |
| Home Depot | ~38 for 4, about 10 each | Panel is 12 x 72; can be cut into 4 (12 x 16) panels. | Page | |
| 20 x 24 | Home Depot | ~25 | Panel is a 24x24 square. Ideal for small number | Page |
| Amazon | ~30 | Panel is 24x24, in polycarbonate | Page | |
| 25 x 36 | Home Depot | ~36 | Panel is a 24x36 square. | Page |
Custom Plastic Panels
Acme Plastics sells plastic sheets online, in many kinds, thicknesses, and sizes. They also have a cut-to-size service: https://www.acmeplastics.com. Shipping is a significant cost.
Tempered Glass: Custom and Product Pages
Tempered glass panels must be ordered as is, and cannot be modified by hand.
For ordering as-is panels, there are sometimes product listings for pre-made panels that cost significantly less than custom work. At the time of writing, this amazon listing carries affordable squares in useful sizes.
For custom work, the website onedayglass.com offers custom sizes at reasonable prices.
In picking edge treatments, polished is more expensive than ground; ground is sufficient for a printing surface. Note that seamed edges, while the cheapest option for custom work, should not be left exposed; they should be surrounded by tabs or taped.
Laser Cutting Services
For cutting the registration L-brackets, there are several services available in the US with online quoting tools. In addition to many local shops, ponoko.com and sculpteo.com offer fast, affordable processing of thin plastics. Ponoko’s PETG at .04” thick is suitable.
3D Printing Services
For printing shims, there are many local printers owned by all types: individuals, shared fabrication spaces, and professional prototypers.
For online 3D printing services, one available online service is 3dhubs.com. Their site, at the time of writing, quotes ~$6 for one 1/8” clamp shim in PLA. In uploading the design:
- export the STL from onshape in cm, mm, or inches.
- specify PLA as the material on 3dhubs
- color-coding is useful for different commonly-used sizes
Finding Materials and Equipment
Cutting Panels to Size
Many individuals and studios have tablesaws–these can cut a plywood panel that is 4’ wide to any width. Depending on the tablesaw and setup, cutting a panel to length may be challenging, especially if the ends are not square and the panel is wider than 18”. A good alternative is a circular saw or track saw, following a clamped guide lined-up with a square.
Many plywood sellers, such as Home Depot, can make plywood cuts for little money using on-site equipment.
Printing Surfaces
Sheet glass and acrylic, a signficant expense for larger surfaces, can be commonly found in forgotten or spare storm windows and picture frames.