Print and cut foam templates

Once you have modelled a piece in Piece Forge, the Unfold to foam tab flattens it into templates you can print, cut out, and trace onto EVA foam. Everything on this page happens in your browser — nothing is uploaded, and nothing is saved unless you save the design itself.

Choosing how many pieces

A flat sheet cannot follow a curved surface exactly. That is a fact about geometry, not a limitation of the tool, so instead of hiding it we let you choose how much of it to accept. The distortion slider is the main control: tighter means more pieces and a closer fit, looser means fewer pieces and a bit more persuading with your hands.

Under the preview you will see three numbers. Distortion is the worst error on any piece. Seam is how much edge you will be bevelling and gluing — the real cost of a build, and what the tool minimises when it picks a split for you. Foam is the total area, for working out how many sheets to buy.

Keep pieces within one sheet across is on by default. It stops any piece from being wider than your paper, so the sheets tape together in a single column instead of a grid. Turn it off if you would rather tape more and glue less.

Reading a template

• Solid lines are cuts. Cut round the outside of every piece, including its glue tabs.
• Dashed lines are folds. The dashed line at the base of a glue tab is where the tab bends, not where you cut. Lighter dashed lines inside a piece are score lines, drawn only where the surface genuinely creases.
• Seam numbers pair up. Every joint prints the same number on both halves, so two pieces off different sheets can be matched without the model in front of you.
• Bevel angles print along the seam — bevel 22° means cut that edge back 22° from square so the joint closes cleanly. Both halves of a seam get the same angle.
• The arrow points up the piece, and the letter-and-number is its grid position. Mark both on the foam before you separate the pieces.

Which surface to trace

By default the template follows the middle of the foam, not its outer face. When foam bends, the length that does not change is the middle — so tracing the outer face makes every piece slightly too big, and the error adds up over a dozen seams. Change it under Trace along only if you have a reason to.

Crowns and domes

The top of a helmet is not a tube, so it is handled separately. If it is close to flat it prints as one disc. If it is strongly curved it is cut into gores — pie-slice pieces that meet at radial seams — because a curved crown genuinely cannot be one flat piece. Both are normal.

What this cannot do

Unfolding only works on pieces modelled in Piece Forge. An STL you imported and scaled cannot be unfolded — flattening arbitrary geometry is a different and much harder problem. If you want foam templates, model the piece here rather than importing one.