About Glass Cut Patterns

Glass Cut Patterns publishes original stained glass patterns built as vector geometry, not drawn or generated as images. Every pattern is run through the same three cuttability checks, minimum piece width, minimum interior angle, and minimum reentrant curve radius, at whatever panel size you choose, before it is offered for download.

The site exists because most stained glass patterns available online are either fixed to one size, scanned from older printed sources, or produced by an AI image generator with no way to verify that the shapes it drew can be cut in glass at all. Building patterns as geometry first means the same source pattern can be rebuilt at any size within its declared range and rechecked every time, instead of being redrawn by hand for each new size.

Glass Cut Patterns is operated by WEABLE SAS. See the legal notice for company details, or the contact page to get in touch.

Why vector geometry rather than images

An image of a stained glass pattern is a picture of lines. Vector geometry is the lines themselves, with coordinates, angles and radii that can be measured. Only the second can be checked: you cannot ask a raster image whether a piece is 3 mm wide at its narrowest point, and an image tool that generates a pretty panel has no way to know it has drawn a shape nobody can cut.

What the checks are measured against

The three checks run at your chosen panel size, after the cutting margin for foil or lead came has been subtracted, because the margin is what actually decides the finished piece. A pattern whose narrowest piece passes at 16 in and fails at 9 in simply declares a range that starts above that point, rather than being sold at a size where it cannot be built.

What is left to the cutter

Glass selection, grain direction and how much waste to allow are choices the geometry cannot make for you, and they are where a panel gets its character. The guides on this site cover the parts that generalise: how to size a pattern to an opening, how much glass a color needs, and how foil and came differ in practice.

Shop procedure after downloading a pattern

Start by confirming the finished opening, not the visible glass area. Measure width and height in at least three places, top, middle and bottom for width, left, center and right for height. Use the smallest measurement if the panel must fit into a fixed frame, then leave a fitting clearance of about 1.5 mm to 3 mm per side for small cabinet panels and about 3 mm to 5 mm per side for larger windows.

Print the pattern at full size and check the scale before you cut glass. A good control mark is a 100 mm line or a 4 in line measured with a steel rule. If the print is off by more than 1 mm over 100 mm, correct the printer scaling before making copies. Do not use browser shrink to fit, because it can change the final panel size by several percent.

Print one clean copy for the layout board and one copy to cut into templates.
Mark every piece before separating the templates, including color, grain direction and piece number.
Cut all repeated shapes from the same master template, not from copies of copies.
Dry fit each color group before grinding the full panel, because repeated correction on one edge can move a joint line by 1 mm or more.
Keep a simple cutting log when using expensive glass, with the sheet size, usable offcuts and pieces already cut.

For more short technical answers about sizing and use, see the FAQ.

Equipment, tolerances and dimensions to plan for

A stained glass pattern is only as accurate as the tools used to transfer it. A steel rule, a sharp marking pen, pattern shears, a glass cutter, running pliers, grozing pliers and a grinder cover most small panels. For larger work, add a straightedge at least as long as the largest straight cut, a square and a rigid board that will not bow while the panel is assembled.

Most hand cut glass work is controlled within small but visible tolerances. A single piece that is 0.5 mm oversize can often be corrected at the grinder. Ten pieces in a row that are each 0.5 mm oversize can add 5 mm across the panel, which may be enough to make the finished work miss the frame. Check cumulative size early, not only at the end.

Item to control	Practical figure	Why it matters
Printer scale check	Within 1 mm over 100 mm	A larger error changes every piece in the panel.
Typical fitting clearance	1.5 mm to 5 mm per side	The panel needs room for installation and frame movement.
Template cutting error	About 0.25 mm to 0.5 mm	Small template errors become visible at long joint lines.
Grinding correction	Usually under 1 mm per edge	Heavy grinding changes shape and can widen the finished joint.
Dry fit interval	Every 10 to 20 pieces on complex work	Early checks prevent a full panel from drifting out of square.

Frequent mistakes and recovery methods

If the printed pattern is the wrong size, do not compensate by trimming border pieces unless the error is very small and the panel is decorative rather than fitted. Reprint at the correct scale, then compare the old and new copies at the corners and along one diagonal. A diagonal mismatch shows both scale error and possible printer distortion.

If a piece breaks during cutting, first decide whether the break follows a future solder or came line. If it does, the piece may still be usable only if the visual result is acceptable and the structure is not weakened. If the break crosses open glass, recut the piece. For textured or directional glass, place the broken piece on the sheet before recutting so the grain direction and light transmission stay close to the surrounding pieces.

If a gap opens during dry fitting, find the cause before grinding the nearest edge. Common causes are a reversed template, a piece cut on the wrong side of the line, glass thickness pushing tight curves apart or one early piece left oversize. Work backward from the gap and check the last three to five joints. Correcting the true cause usually removes more error than grinding the final piece.

If the panel begins to go out of square, pin or block two straight edges on the layout board and rebuild from that corner. Measure both diagonals. On a rectangular panel, a difference of 3 mm between diagonals is already visible on cabinet scale work. Large architectural panels may hide more, but the frame will still reveal the error during installation.

Special cases that need extra planning

Very small panels need wider visual spacing between detail and border than the drawing may suggest on screen. A 6 mm detail near an edge can look clear on a monitor but become fragile or visually crowded after cutting, grinding and soldering. When reducing a design, check the smallest decorative areas first, not the outside size.

Long narrow panels need support during assembly. A panel that is 200 mm wide and 900 mm tall can twist on a flexible board even when every piece is correct. Use a flat board, keep the border pinned and move the work as little as possible before it is soldered or cemented.

Mirrored pairs, door panels and sidelights should be planned as a set. Print both orientations and mark the viewing side before cutting any textured glass. If the same pattern is used on opposite sides of a doorway, the grain direction may need to mirror as well, otherwise the panels can reflect light differently even with the same colors.

For repair work, size the pattern from the surviving opening and from the old glass thickness, not from a photograph. A phone image can help identify shapes, but lens distortion near the edge can shift a line by several millimeters. Tape a physical tracing over the opening when possible, then use the downloaded pattern as the clean working geometry.