3D file checklist: formats, naming and sending

Most quoting delays come down to the file, not the design. Wrong format, unclear units, or ten parts merged into one STL, and we have to come back and ask before we can price it. Run through this checklist before you upload, and your quote comes back faster and more accurate.

1. Use the right format

• STL is the safest default. Every printer and slicer reads it, and it’s what we need for the print itself.
• STEP if you want us to review or edit the design before printing. We can open and modify STEP files; STL is just a fixed mesh, so we can’t refine it the way we can a STEP.
• 3MF or OBJ with a texture for parts that need to hold colour, since plain STL carries geometry only, no colour or material data.
• Avoid exporting from specialty CAD software (Rhino .3dm, SolidWorks .sldprt) without converting first, unless you’ve confirmed with us that we can open the native format.

2. Check your units before exporting

STL files carry no unit information, only numbers. If your software’s export defaults to inches and ours reads it as millimetres, dimensions shrink by a factor of roughly 25 (a part meant to be 100mm comes out around 4mm). Confirm your export is set to millimetres before you save, and mention the intended real-world size in your message if there’s any doubt.

3. One file per part, not one file per assembly

If you’re printing several parts, keep each one as its own file rather than merging them into a single STEP or STL. A merged file can’t be priced, sliced, or coloured per part, and if only one part needs a design tweak, we’d have to untangle it from the rest first.

• Multiple parts for one project: export each separately, then zip the folder for upload.
• One part made of several bodies (e.g. a single sculpted object): merge those into one STL before export, so it prints as intended.

4. Name files so we don’t have to guess

A folder of Part1.stl, Part2.stl, New Folder (3) slows down quoting on our end and reordering on yours. Use a naming pattern that carries the details a quote needs:

ProjectName_Material_Color_Quantity

For example: DeskStand_PLA_Black_x2.stl. If material or colour isn’t decided yet, leave that segment as TBC rather than dropping it, so the structure stays consistent across files.

5. Send it through

• Instant quote: upload your file at /3dprint and get pricing without waiting on email back-and-forth.
• Email: fine for files under 25MB, or when you want to talk through the job first, at sales@additiveinn.com.
• Larger files (big assemblies, scan data): a Google Drive, Dropbox, or WeTransfer link is easier than an attachment.

We flag watertightness, wall thickness, and other printability issues during quoting if we spot them, but a file that’s already in the right format, in the right units, and clearly named gets through that step a lot faster. For the design-side rules, wall thickness, overhangs, tolerances, see our guide to preparing 3D files for printing.