Reducing Polygons for 3D Printing with Decimation Master

Author: Arndt von Koenigsmarck · Technical review by Paul Gaboury · Last reviewed August 2026 

A finished ZBrush sculpt can easily reach tens of millions of polygons, which is far more than most printers, slicers or print services will accept. ZBrush Decimation Master solves this by reducing the polygon count dramatically while preserving the surface detail that makes the model worth printing. This guide explains how and when to use it. It is part of the wider guide to ZBrush and 3D printing.

Slicers turn your model's surface into printer instructions, and an unnecessarily heavy mesh slows that process, inflates file sizes and can exceed the limits of print software or online services. The goal is a model light enough to handle smoothly but dense enough that curved surfaces and fine detail still read once printed. Decimation is how you hit that balance, because unlike uniform subdivision it concentrates polygons where the detail is and removes them from flat areas.

Decimation Master is a plugin that ships with ZBrush. The basic workflow is:

1. Open ZPlugin > Decimation Master.

2. Click Preprocess All (or Preprocess Current) so ZBrush analyzes the mesh. This step can take a little time on heavy models.

3. Set your target, either as a percentage of the original, or as a specific polygon count.

4. Click Decimate All (or Decimate Current) to apply it.

Preprocessing is what lets you then decimate quickly to any target, so you can try a few levels and compare.

• Keep and freeze borders preserve open edges and boundaries, which matters if a part must line up with another.

• Use and Keep Polypaint retains PolyPaint through decimation, which is useful if you plan to print in color via a format that carries it, such as VRML, OBJ, STL or 3MF. It also lets the PolyPaint drive the decimation itself: you can paint the areas where you want detail kept, and Decimation Master will distribute more triangles there, preserving density exactly where it matters.

• Masking gives you another way to steer triangle distribution: mask the areas you want to keep dense before preprocessing, and Decimation Master will concentrate more triangles there while thinning the unmasked areas more aggressively.

• Per-SubTool control lets you decimate each SubTool to a suitable level rather than treating everything the same, so a smooth base can be reduced more aggressively than a detailed face.

There is no single correct number, because it depends on the size of the print and the detail involved. As a practical guide, 300,000 to 1,000,000 polygons is often plenty for small to medium prints, and you can go lower for simple shapes. The reliable test is visual: decimate, look at the silhouette and the key detail areas, and if they still hold up, you have gone far enough. If facets appear on smooth curves or detail softens, raise the target. Finding the right value is quick, because you only need to preprocess the model once per session. After that first Preprocess, you can keep changing the target and clicking Decimate as often as you like without processing the mesh again, which frees you to try several values and settle on the perfect polygon count.

Decimate near the end, after the model is watertight and hollowed, and just before export. Keep your full-resolution sculpt saved separately, so you always have the original to return to if you need to change something or re-decimate to a different target. Once decimated, the model is ready for the final step, covered in how to export STL from ZBrush.

Next: export your optimized model in how to export STL from ZBrush with the 3D Print Hub.