NOTES FROM THE WORKBENCH
A triangular box for a small keepsake
A triangular package is defined by its section, so compare the object with the sloping sides before making a full-length model.
Reviewed October 27, 2026
Use an equilateral sketch
FoldParcel's triangular prism has an equilateral section. With a side length of 40 mm, its height is about 34.64 mm. The 40 mm width and 34.64 mm height describe the triangle's enclosing rectangle, not a rectangle that fits freely inside it.
Draw the section on plain paper and place the outline of your keepsake over it in the intended orientation. A corner near the apex is often more restrictive than the widest part at the base.
Reserve room at the ends
Prism length runs between the two end faces. The end tabs and the material folds occupy practical space near those faces. An object whose measured length exactly matches the fold-line length has no deliberate room for those details.
The example's three 40 mm side panels plus a 10 mm glue tab make a 130 mm-wide band. That band width is not the prism's length or its section height.
Check the opening sequence
Make a plain trial and close one end. Insert the object without distorting the triangular section. Try removing it again before fixing the other end. A long narrow object may need access through an end that your decorative concept had treated as permanently closed.
Mark the intended display face on the sample. Rotating the prism changes whether a flat panel or a ridge is uppermost, and it changes where the seam can be hidden.
Keep a rectangular alternative beside it
Generate a tuck or two-piece option for the same object and compare the actual paper layouts and handling. The triangular option may be chosen for its form, but it is not automatically more economical or stronger.
Save the version and its section sketch. Record any physical trial observations separately from the generator's mathematical dimensions so that a successful paper sample is not mistaken for a general manufacturing guarantee.
Ready to make something?
Set the dimensions. Check the folds. Make a small test box.