Movement Tray Spacing
What spacing should you choose for your movement trays? That's a great question, and it's not one that can be answered by us easily. The best thing to do is to print out one of our Spacing Helper PDFs and place your models on the paper. This will give you an accurate idea of how the spacing will be for your movement trays.
Spacing Helper PDFs
If you're in the United States and print with "Letter" size paper (8.5" x 11").
If you're pretty much anywhere else and print with "A4" size paper (210 x 297 mm).