Print Orientation Best Practices for 3D Printing

How a part is oriented on the build platform affects strength, surface finish, accuracy, support requirements, and cost. Orientation is one of the most impactful decisions in 3D printing.

1. Key Principles

Strength — Parts are weakest between layers (Z-axis). Orient so the primary load direction runs parallel to the layers, not perpendicular.

Surface quality — Upward-facing surfaces are smoothest. Downward-facing surfaces (in contact with supports) are roughest. Orient so cosmetic surfaces face up.

Supports — Minimize overhangs that require support material. Each support mark is a surface imperfection that needs cleanup.

Accuracy — XY dimensions (within a layer) are more accurate than Z dimensions (across layers). Orient critical dimensions in the XY plane.

Print time — Taller parts (more layers) take longer. Orienting a part on its side can significantly reduce print time and cost.

2. Orientation by Application

Functional / structural parts: Orient so the layer lines run parallel to the expected load. A bracket that will be pulled downward should have layers running horizontally.

Visual / presentation models: Orient so the most visible surface faces upward (away from supports). Accept longer print time for better cosmetics.

Thin-walled parts: Orient vertically to avoid long unsupported spans. Horizontal thin walls sag without support.

Parts with holes: Vertical holes (along Z-axis) are more round and accurate. Horizontal holes may be slightly oval.

3. Technology-Specific Notes

FDM: Orientation matters most. Layer adhesion is the weakest point. Supports leave significant marks.

SLA: Orientation affects drain holes (for hollow parts) and support placement. Less strength anisotropy than FDM.

MJF: Orientation matters least. No supports needed. Parts are nearly isotropic. Still orient for surface quality on critical faces.

4. How to Specify Orientation

Include a note with your order specifying which surface is most important or how the part will be loaded. You can also include a screenshot showing your preferred orientation.

Or select “Tech’s Choice” and our engineers will optimize orientation for the best balance of strength, surface quality, and cost.