Preparing your file

File types

• STL and OBJ: the most common 3D printing files.
• STEP (.step, .stp): exported from CAD programs such as Fusion, SolidWorks or Onshape. Exact curves, so holes come out round.
• 3MF projects from Bambu Studio, OrcaSlicer or PrusaSlicer: we read your colors, filaments, every object and your print settings (walls, fill, layer height).
• Several files or a .zip (a whole download from a model site): drop them together. They open as one project, with a count for each piece; other versions of the same model start at 0, so you only pay for what you want.
• Files up to 500 MB. Very detailed files open on our server automatically when they’re too big for a phone.

Units and size

• We read sizes in millimeters. STL and OBJ files don’t say which unit they use, so check the size shown on the price page.
• A unitless file smaller than 12 mm is probably in inches: we ask you which it is. For any other file, you can switch to inches under Advanced options.
• You can scale a part up or down on the price page. Anything other than 100% is clearly marked on your order.
• Use Measure on the price page to check a distance between two points before you order.

Multi-color and multi-part projects

• Paint your model or give each part its own filament in your slicer, then save the project (.3mf), not just an exported STL.
• Each color is matched to the closest one we stock; you can change any of them on the price page. See multi-color printing for limits.
• Projects with several objects show Objects in your file: set how many of each you want, or 0 to leave one out.

Exporting from CAD

• STEP is best from CAD programs (Fusion, SolidWorks, Onshape, FreeCAD, Inventor): it keeps exact curves and its units.
• Exporting an STL? Choose a fine or high resolution, so circles and curves come out smooth instead of flat-sided. Choose millimeters if the exporter asks.
• Export each part as its own body. Several parts in one file are fine: they show up as separate objects you can count, recolor or leave out.
• From Tinkercad, SketchUp or Blender: STL or OBJ works. In SketchUp and Blender, check the size on our price page (they often export in other units).

Common problems and fixes

• Part is tiny or huge: the file used other units. Switch inches/millimeters under Advanced options, or use Scale.
• “Gaps” warning: the surface has holes (common in models made for games or animation). Most still print; the engineer review tells you if one won’t. Repair tools in your slicer or CAD program fix most of them.
• Walls too thin: models made for screens often have paper-thin walls. Thicken them to at least 0.8 mm (see the design guidelines).
• Colors missing: an exported STL has no colors. Upload the slicer project (.3mf) instead, or give each piece a color on the price page.
• File too big for your phone: very detailed files open on our server automatically. On a computer, files up to 500 MB open in the browser.

Before you order

• Watertight: the model should be a closed shape with no gaps. We check this and warn you; most CAD exports are fine.
• Orientation: save the part the way you’d like it printed. We keep it, unless another side needs far less support.
• Fit and strength: check holes and walls against the design guidelines.
• Rights: you need the right to have the design printed. For downloaded models, check the license allows printing by a service (see where to find models).

No file at all? Make a part from a template, or describe what you need.