Learn & Understand

Choosing Layer Height for the Part's Purpose, Not Just Its Geometry

Two prints can both sit comfortably inside the "safe" 25-75% nozzle diameter range and still be using the wrong layer height for what the part is actually meant to do.

Display Pieces: Optimize for What the Eye Notices

A miniature, figurine, or anything meant to be picked up and looked at closely benefits from layer height chosen toward the finer end of the safe range, since visible layer lines are the single most common giveaway that an object was 3D printed rather than manufactured another way. For these parts, the extra print time cost of a finer layer height is usually worth paying, and - as covered in this category's staircase-effect guide - matters especially on any curved or sloped surfaces the piece has, where coarser layers show up as visibly stepped terracing rather than a smooth curve.

Functional Parts: Optimize for Strength and Turnaround, Not Looks

A bracket, enclosure, jig, or replacement part that will be hidden inside an assembly or judged purely on whether it works has very different priorities. Layer lines are irrelevant if nobody will see them, and a coarser layer height within the safe range often prints meaningfully faster with negligible impact on the part's actual mechanical function, since layer height has a much smaller effect on strength than infill percentage and pattern (covered in this category's infill guide). For purely functional, hidden parts, defaulting to the fast end of the safe range rather than the fine end is usually the better tradeoff.

Vase Mode: A Genuinely Different Set of Rules

Vase mode (also called spiralize outer contour mode) is a special printing technique that produces a single continuous spiraling wall with no internal infill, top layers, or multiple perimeters at all - commonly used for vases, lampshades, and simple decorative containers. Because there's no need to bond a new wall to multiple perimeters or internal infill at each layer transition, some of the standard bonding-strength logic behind the 25-75% guideline applies differently here: many vase mode prints intentionally use a relatively fine layer height for a smooth surface finish, since the print time savings a coarser layer height would normally offer matter less on these typically small, single-wall, fast-printing objects to begin with, and surface smoothness is usually the entire point of a vase mode print.

Making the Choice Deliberately

Before defaulting to whatever layer height a slicer profile happens to suggest, ask what the specific part is actually for - a hidden bracket and a display miniature both fall well within the same "safe" range this calculator recommends, but the right choice within that range is genuinely different for each.