File Preparation Guide
Get the best results from your 3D prints by following our comprehensive file preparation guide. Properly prepared files mean fewer issues, faster turnaround, and prints that match your vision.
File Format
STL, OBJ, or 3MF
Min Wall
1.2mm thickness
Min Detail
0.4mm features
Geometry
Manifold/Watertight
Scale
Millimeters (mm)
Max Size
200 × 200 × 200mm
Accepted File Formats
We accept the most common 3D printing file formats
.STL
StereolithographyThe industry standard for 3D printing. STL files describe only the surface geometry of a 3D object without color or texture information.
- Universal compatibility
- Supported by all slicers
- Smaller file sizes
- Best for single-color prints
.OBJ
Wavefront ObjectA more complex format that can include color, texture, and material information. Often paired with .MTL files for textures.
- Supports vertex colors
- Can include textures
- Wide software support
- Good for multi-color prints
.3MF
3D Manufacturing FormatA modern format designed specifically for 3D printing. Contains mesh data, colors, materials, and print settings in one package.
- All-in-one package
- Preserves print settings
- Better error handling
- Growing industry adoption
Export Tips
Use Binary STL
Binary STL files are 5-10x smaller than ASCII STL files with no quality difference.
Check Units
Ensure your modeling software is set to millimeters before exporting. Inches will result in prints 25x larger than expected.
Include Textures
If using OBJ format with textures, zip the .obj, .mtl, and texture files together.
Common Issues & How to Fix Them
Most file problems can be fixed with the right tools and knowledge
What is it?
Non-manifold geometry occurs when a mesh has edges shared by more than two faces, holes in the surface, or internal faces. This makes the model "non-watertight" and impossible to slice properly.
Common Causes
- Overlapping or intersecting geometry
- Internal faces not deleted after boolean operations
- Missing faces or holes in the mesh
- Edges with only one connected face
- Duplicate vertices at the same location
How to Fix
- Blender: Select All → Mesh → Clean Up → Make Manifold
- Meshmixer: Analysis → Inspector → Auto Repair All
- Windows 3D Builder: Opens and auto-repairs most issues
- Netfabb: Automatic repair tool for complex issues
What is it?
Face normals indicate which side of a polygon is "outside." When normals point inward, the slicer may interpret solid areas as hollow or cause other printing errors.
Common Causes
- Scaling with negative values
- Importing from different software
- Boolean operations gone wrong
- Manual face creation in wrong direction
How to Fix
- Blender: Select All → Mesh → Normals → Recalculate Outside (Shift+N)
- 3ds Max: Modifier → Normal → Flip Normals or Unify Normals
- Fusion 360: Mesh → Modify → Repair Body
- Visual check: Enable "face orientation" view to see inside (red) vs outside (blue)
What is it?
Walls thinner than 1.2mm may not print reliably with FDM technology. They can result in weak, brittle parts or may not print at all if thinner than the nozzle diameter.
Common Causes
- Model designed for different manufacturing process
- Scaling down a larger model
- Decorative details not meant to be structural
- Game or movie assets not designed for printing
How to Fix
- Blender: Use Solidify modifier to add thickness
- Meshmixer: Edit → Offset to thicken walls
- Fusion 360: Shell command with offset value
- Best practice: Design with 1.2mm minimum wall thickness from the start
What is it?
FDM printing builds layer by layer from the bottom up. Any geometry that extends outward at more than ~45° from vertical has nothing to print on and will sag or fail.
Common Causes
- Arms, weapons, or appendages extending horizontally
- Undercuts and recessed areas
- Bridges spanning large gaps
- Models designed for other manufacturing methods
How to Fix
- Reorient: Rotate the model so overhangs become less severe
- Split the model: Print in pieces and assemble
- Add supports: We add supports as needed during slicing
- Design modification: Add chamfers or fillets to reduce overhang angles
What is it?
Your model's dimensions don't match what you intended. A 50mm miniature might import as 50 inches (1,270mm) or 0.05mm—both unusable.
Common Causes
- Software set to inches instead of millimeters
- Scaling applied before export not saved
- Different unit systems between applications
- Downloaded files with unknown original scale
How to Fix
- Before export: Set your software to millimeters in preferences
- Verify dimensions: Check model size matches expected dimensions
- Common conversions: If 25.4x too large, original was in inches
- Include reference: Tell us the intended size when ordering
Design Optimization Tips
Get the best possible results from your prints
Print Orientation
The direction a model is printed significantly affects strength, detail, and support requirements.
- Strongest along the X/Y plane (horizontal layers)
- Weakest between layers (Z direction)
- Orient critical features horizontally
- Position flat surfaces on the build plate
Minimize Supports
Supports are necessary but leave marks and use extra material. Design to reduce them.
- Keep overhangs under 45° when possible
- Add chamfers to bottom edges
- Convert overhangs to 45° angles
- Consider splitting and assembling
Text & Fine Details
Small features need special consideration for FDM printing.
- Minimum text height: 5mm
- Embossed/engraved depth: 0.5mm minimum
- Use bold, sans-serif fonts
- Orient text horizontally on print bed
Holes & Tolerances
Printed holes are typically smaller than designed due to material shrinkage.
- Add 0.2-0.4mm to hole diameters
- For press fits, add 0.1-0.2mm clearance
- Vertical holes print more accurately
- Test critical tolerances with a sample print
Recommended Software
Tools to help prepare and repair your 3D models
Free Tools
Blender
FreePowerful open-source 3D modeling software. Excellent for modeling, repairs, and mesh cleanup.
Meshmixer
FreeAutodesk's free mesh editing tool. Great for repairs, supports, and combining meshes.
Windows 3D Builder
FreeBuilt into Windows 10/11. Simple but effective for basic repairs and viewing.
PrusaSlicer
FreeSlicing software with built-in mesh repair and analysis tools.
Professional Tools
Fusion 360
Free for PersonalProfessional CAD software with mesh repair tools. Free for hobbyists.
Netfabb
PaidIndustry-standard mesh repair software. Handles complex repairs automatically.
Online Tools
Microsoft 3D Viewer
FreeQuick online viewer to check your models without installing software.
Tinkercad
FreeBrowser-based CAD tool. Great for beginners and simple edits.
Need Help With Your File?
If you're having trouble preparing your file or just want a professional to review it before printing, we're here to help.
Questions?
Our team is happy to help with any file preparation questions.
Pre-Upload Checklist
Run through this checklist before submitting your file
All checked? Your file is ready to upload!