Print at the right size
Choose your paper, A4 or Letter, under Grown-ups › Paper. On the Print tab, pick a size, from egg to beach ball, or type a height in centimetres. Big models are split across as many pages as they need.
Print at 100% ("Actual size"), never "Fit to page". Every page has a black bar that should measure exactly 10 mm. If it doesn't, the pieces won't fit together: print again at 100%.
Choose Colour, Colour it yourself (outlines only) or Ink saver.
No printer?
Tap Save as PDF. The share sheet opens: save the PDF to Files, AirDrop it, or email it to a computer with a printer. Print it from there at 100%.
Cut, fold and glue
- Cut along the solid lines. Scissors are sharp: younger children should cut with a grown-up.
- Fold along the dashed lines, away from you, so the print stays outside. A dash-dot line (a few dented shapes have them) folds the other way, towards you. Fold everything before gluing anything; a ruler and the back of a butter knife make crisp folds. The cover page of every printout shows these lines.
- Each glue tab has a letter. Glue it under the edge with the same letter on another piece. The Fold tab shows every step in 3D, using the exact pieces you printed.
A glue stick or white craft glue works best. Thin card (160–200 g/m²) makes sturdier models than copy paper.
Packs, prices and Restore Purchases
Polyhedra is free to download, with six shapes, every lesson and all printing included. More shapes come in packs: one-time purchases, no subscription, yours to keep. Everything includes every pack, and every pack added later.
Packs are shared with your family through Family Sharing. On a new device, or after reinstalling, open Grown-ups and tap Restore purchases.
If a child asks to buy with Ask to Buy turned on, the app shows "Waiting for a parent to approve" and the pack unlocks as soon as it is approved.
Refunds go through Apple: reportaproblem.apple.com.
The grown-up check
Buying, Restore Purchases and the settings are behind a short sum written in words, for example "What is twelve plus seven?". Type the answer on the number pad and tap Continue. A child can still look at, spin and learn about every shape without it.
The read-aloud voice
Tap the speaker button on a screen to hear it read aloud. To have every fold step read out, turn on Read each fold step aloud under Grown-ups. The voice is pre-recorded synthetic speech inside the app, so it works offline. On iPhone, it plays even with the silent switch on.
Contact us
Email apple@ai-bistro.com. Tell us your device, the shape, and the paper and size you chose. A photo of the printed page helps with printing problems. Please don't send us a child's personal details.