What each file type is, when to pick it, and how to export it cleanly from Fusion 360, SolidWorks, Blender or Tinkercad.
STL
STL is the oldest and most widely supported 3D printing format. It stores only the outer surface of your model as a mesh of triangles: no units, no colour, no material data. Almost every CAD and sculpting tool exports it, and our upload page measures it in seconds. Pick STL when you need one solid part and maximum compatibility.
Export tips: Fusion 360 and SolidWorks both offer saving as STL, set the resolution to fine or high. In Blender, apply scale before exporting. Tinkercad exports STL straight from the Export button.
3MF
3MF is the modern successor to STL. One file carries real units, colour, textures and several parts at once, so nothing gets lost on the way to the printer. When your software can export 3MF, choose it over STL: fewer questions from us, fewer surprises for you.
Export tips: current Fusion 360, SolidWorks, PrusaSlicer, Orca and Bambu Studio all write 3MF. Saving the whole build plate from your slicer as 3MF also keeps orientation and colour assignments.
STEP / STP
STEP (or STP) is an exact CAD format: real curves and real units instead of triangles. It is the best choice for engineering parts with tight dimensions, threads or press fits, because we can adjust the geometry for printing without quality loss. Upload a STEP file and the configurator prices it like any other model, and only what the automatic price refuses goes to a quote request.
Export tips: in Fusion 360 use File, Export, STEP. In SolidWorks, save as STEP AP214. Tinkercad cannot write STEP, so export OBJ or STL there instead.
OBJ
OBJ is a mesh format that carries colour and texture through a companion MTL file and image textures. It is common in 3D scanning and sculpting, and it works well for figurines and display models. Remember that the textures live in separate files: send them together with the OBJ in one ZIP.
Export tips: in Blender, export OBJ with materials enabled and pack the .obj, .mtl and texture images into one ZIP. Most scanning apps offer OBJ with textures as a standard export.
GLB (glTF)
GLB is the binary form of glTF: mesh, materials and textures packed into a single file. Phone scanning apps and modern sculpting tools often save GLB by default, and web viewers use it too. It is a good choice for colour models because nothing can go missing: one file holds everything.
Export tips: in Blender choose glTF 2.0 and the GLB variant. If your scanning app offers GLB or OBJ, GLB is the easier one to send: no loose texture files.
JPG / PNG
A JPG or PNG is not a 3D model, but it is often the real starting point. Send photos of a broken part you need replaced, or of a thing you want made. AI 3D Studio turns a photo into a model automatically, and an engineer models one by hand when you ask for it in a quote request.
Photo tips: shoot from several angles in daylight, keep the part in focus, and lay a ruler or a coin next to it so we can judge the scale.
PDF
A PDF drawing carries what a photo cannot: exact dimensions and tolerances. Send it with a quote request, together with a model or photos, and the engineer works to the dimensions on the drawing. For simple parts, a clear drawing alone can be enough to model and print from.
Drawing tips: export the PDF directly from CAD rather than scanning paper, keep dimensions readable, and include at least the overall size of the part on one view.
Units and colour: where files usually go wrong
STL and OBJ carry no units at all. A part drawn as 50 millimetres can open as 50 inches somewhere else, which is why we assume millimetres and the upload page shows you the measured size before you order. STEP, 3MF and GLB store real scale, so they travel more safely.
Colour is similar: STL and STEP never carry it, while 3MF, OBJ with textures and GLB can. A printed part gets the colour of its filament, so the colours in your file are only a guide: you pick the printed colour in the configurator.
Format
Keeps units
Keeps colour
Measured on upload
STL
No
No
Yes
3MF
Yes
Yes
Yes
STEP / STP
Yes
No
Yes
OBJ
No
Yes
Yes
GLB
Yes
Yes
Yes
No in the units column means we assume millimetres and show you the size we measured on the upload page, before you order anything.
What happens after you send a file
Two roads, depending on the file. Models are measured and priced by the upload tool in seconds; drawings, photos for hand modelling and anything the calculator refuses go to a quote request.
Measured in seconds
STL, 3MF, STEP, OBJ and GLB up to 100 MB. Drop the file on the upload page and see its real size, volume and part count before you order anything.
PDF drawings, photos that need a person to model them, and models the automatic price refuses: bigger than the 325 x 320 x 325 mm plate, over 500 EUR a line before VAT, or a delivery country we have no rate for. Attach them to a quote request and an engineer replies by email.
The price appears on the screen with VAT and delivery included, and you pay by card. Only what the calculator cannot price goes to an engineer, who answers your quote request by email.
File format questions
Can I send a ZIP archive?
Yes. Pack several models, or an OBJ with its textures, into one ZIP of up to 100 MB. We unpack it and check every file inside.
My file is over 100 MB. What now?
Export it again with a lower mesh resolution: most parts print exactly the same from a much smaller file. If it stays large, send us a file sharing link at info@3dpartgo.com.
Which format keeps colour?
3MF, GLB and OBJ with textures carry colour information. STL and STEP do not. The colour you get is the one you pick in the configurator.
My model has no units. Will the size be wrong?
No. STL and OBJ simply have no units, so we assume millimetres and show you the measured size on the upload page, before you order.
Can you fix a broken mesh?
The upload check tells you what it found: whether the surface is closed, how many separate bodies there are and whether the volume can be measured. A model we cannot measure gets no automatic price, so send it with a quote request and an engineer replies by email.
I only have a photo of the part.
Send it anyway. AI 3D Studio builds a model from a photo automatically and the price appears on the screen. For a technical part an engineer models from photos plus a few measurements when you ask through a quote request.
Send the file you have
Upload a model and see the price with VAT and delivery in seconds, or send a drawing or a photo with a quote request and an engineer replies by email.
