Original, editable studies
A starting point for your next panel
Choose a finished study to load its working geometry. Change the piece count, inspect a shape, or export directly from the workshop.
From an idea to a numbered cutting pattern
- Choose an example or upload a local image. Set the real panel size, then request 10–120 pieces and make the pattern. Begin with 24 pieces when comparing detail with cutting effort.
- Select a numbered piece and read its dimensions. Review narrow widths and deep corners, merge only neighboring regions where useful, and compare the remaining risks after each repair.
- Choose the construction heart, glass materials and print setup. Preview the tile grid, download a free file, and measure its printed ruler. Save the editable project before closing the tab.
Start with the design, then choose the cut
The loaded kingfisher is an editable composition, not a preview image. Change 36 pieces to 24 and make the pattern again: the engine rebuilds closed regions, places labels inside them, and updates the glass key. Increasing the count can preserve a wing or branch, while reducing it makes the drawing broader. The requested count is shown separately from the number that can meet the selected minimum width.
For a 16 × 20 inch panel, the canonical drawing is 406.4 × 508 mm. Set those physical dimensions before deciding whether a narrow shape is usable. A 10 mm strip in a small suncatcher may become much wider when scaled to a door panel. Changing from inches to millimetres converts the existing dimensions; it does not multiply the design twice or merely change a unit label.
Read the cutting report on the drawing
Minimum piece width is a geometric strip or interior neck measurement, not a minimum area. A long 10 × 100 mm strip has 10 cm² of area but is still only 10 mm wide. Move the threshold from 10 to 15 mm and that strip needs review. Select a risk to locate its piece, then merge it with a real neighbor if the resulting outline is easier to cut.
The automatic merge chooses a shared boundary; manual merge requires two neighboring regions. Both operations produce a new outline, renumber the drawing and recalculate the report. Undo restores the preceding geometry and settings. A merged outline can still have a deep corner, so fewer pieces do not guarantee fewer risks. A deep concavity may need grinding, a different division, or a different composition.
Choose the right glass preview
Cathedral, Opalescent, Streaky and Textured previews help separate transparent color, milky opacity, directional streaks and surface texture. They are flat digital approximations, not manufacturer glass codes or a daylight simulation for a particular building. Edit one selected piece without recoloring every other piece that shared its original glass key.
Switch to the numbered cartoon when planning score lines and back to the glass view to inspect color balance. Keep the seam heart independent from the visible face width. Copper foil at 0.8 mm means a 0.4 mm inward cutting offset; lead came at 2.0 mm means 1.0 mm. That change reduces the actual glass area even if the panel dimensions and the displayed seam color stay the same.
Centerlines, cutting lines and actual glass
A centerline cartoon describes how the panel fits together. A cutting contour describes the smaller piece of glass that fits beside the seam. Keep the two files clearly named in the workshop: tracing the centerline as a cut line would leave too little room for the chosen heart. The preview seam finish is cosmetic; black patina, copper and silver grey keep the same physical boundaries.
The material table integrates the compensated polygons, then groups their areas by glass ID. A 25% waste allowance multiplies the net area by 1.25; it does not turn irregular shapes into a guaranteed shopping list. Sheet nesting answers a different question by placing actual cutting contours inside a selected sheet, with a 5 mm edge margin and 3 mm gap by default. A piece that cannot fit is reported rather than silently omitted.
A project you can inspect and keep
Select any numbered shape to see its cut width, height and net area. The bounding dimensions help you find a blank large enough for that piece; net area measures its polygon, so a triangle is not counted as its full enclosing rectangle. The glass list is separate from the piece numbers: two blue pieces can have different IDs but use the same material.
Save a local .sgpattern.json project before leaving the page. There is no automatic browser draft or cloud gallery. Reopening the file restores the millimetre geometry, numbering, palette, material and cutting settings. An invalid project or failed image decode leaves the last valid pattern available. A maximum of 200 imported pieces and 512 vertices per piece keeps inspection and file generation bounded.
Match the file to the workshop task
For a small suncatcher, use the free single-layer inset SVG and the paper cartoon together. For a larger panel, keep the tiled PDF at actual scale. If you are preparing layered sticker dies, matching pieces to stock sheets, or selling teaching packs, the three workshop ZIPs provide those specific production documents.
Use the copper foil guide for the 0.8 mm heart and tape-width calculation, the lead came guide for 1.6–2.0 mm hearts and frame allowances, and the printing guide for measured 1:1 tiles.
Cutting difficulty and glass quantities are based on planar geometry and the selected waste allowance. Adjust the real cutting plan for glass texture, material and the tools you use.
Before you score the glass
Which files can I download for free?
Every basic export is free and unlimited: cartoon or backlit PNG, centerline SVG and DXF, single-layer inset SVG, full-size tiled PDF, material PDF and CSV, and a local project file. The tiled PDF includes a stainedglasspatternmaker.com footer. The other basic vector and image exports have no watermark.
Does the tool upload my photo?
Photos are decoded, resized and segmented in browser memory. Free exports also stay in the browser. A paid production export sends only the calculated vector pieces and necessary settings to the site server; the seller pack also sends your optional studio name and notes. These inputs are processed in memory and are not saved.
Why do the cutting lines move when I change construction?
A seam needs physical room between neighboring glass pieces. Copper foil uses a 0.8 mm heart and moves each edge inward by 0.4 mm. Lead came settings use a 1.6 or 2.0 mm heart, with 0.8 or 1.0 mm inset. Preview line thickness does not change these offsets.
Can every numbered shape be cut in one score?
No. The report flags narrow pieces and deep re-entrant corners, but planar geometry cannot predict every break in real glass. A 270-degree corner may need grinding or a different split. Review the advice, merge only neighboring pieces, and keep unresolved warnings in your cutting plan.
How do I print the pattern at its real size?
Choose Letter or A4, set orientation, printable margins and overlap, then download the full-size PDF. Print at 100% or Actual size, with fitting disabled. Measure the 100 mm or 4 inch calibration ruler on paper before cutting. Construction page counts exclude the overview page.