PLY file: what it is and how to prepare it for printing

Where PLY comes from

The PLY format was devised at Stanford University in the mid-1990s to store data from 3D scanners. The file is simple and exists in a text and a binary version. Besides the positions of points, it can store colour, transparency or normals. The Library of Congress also has a technical description.

You will meet it in 3D scanning and photogrammetry. Mobile apps and scanners often export PLY precisely because they keep colour in the points rather than in a texture.

Why the printer cannot take it directly

Our calculator accepts STL, 3MF, OBJ and STEP, but not PLY. The reason is practical: a scan is often a point cloud or a dense mesh with holes, and printing needs a closed, solid object. Colour stored in points also cannot simply be carried over into the material. We print only in PLA and PETG, where each colour is a separate filament, so you cannot print a fine colour gradient from a scan.

What to do with a scan before ordering

1. Open the PLY in a program such as Blender or MeshLab and fill the holes.
2. Make sure the model is closed, see closed model.
3. Reduce the number of triangles if there are millions. Above 50 MB the file would not fit into the calculator.
4. Export as STL, or as 3MF if you want to assign colours part by part.

We also repair small holes automatically and will tell you about bigger errors before printing starts. Check the size of the scan, because it is often at a different scale than you expect, and you can set that in the calculator.

Important for scans from a phone

Scans from a phone or a handheld scanner often have bad edges, floating bits and cavities. Remove them before printing, otherwise they print as useless protrusions. Keep in mind too that a scan is often just a surface, not a solid, so the wall has to have some thickness. A model with zero thickness has nothing to build from.

We print from 1 to 5,000 pieces, so if someone has actually ordered your scan in quantity, the calculator shows the price per piece at your quantity right away.