Think in stages, not numbers
Abrasive stages have different jobs: correcting visible form, replacing the previous scratch pattern, and preparing the surface for its final treatment. The printed part decides how much correction is needed. A useful sequence is therefore defined by clear handoff conditions rather than a memorized list of numbers.
When to start coarse
More aggressive correction is justified only when the defect requires it and the geometry can tolerate it. Broad faces, sharp transitions, recesses, and small details do not carry the same risk. Begin with the least aggressive approach that can make measurable progress, then inspect before changing course.
When to move up
Move forward when the current defect has been replaced by a uniform, controlled surface pattern. Touch alone is not enough: directional light reveals isolated ridges, cross-scratches, low areas, and rounded edges. If the evidence is mixed, the surface is not ready for the next stage.
Dry vs wet sanding
Dry and wet abrasion solve different problems. The choice depends on the material, the correction stage, heat management, dust control, and whether the abrasive is designed for wet use. Follow tool and abrasive guidance, and keep water away from electrical equipment not rated for it.
Edges need a different touch
Every geometry needs its own support and pressure strategy. Flat faces must remain planar, curves must keep their radius, and intentional edges must stay readable. A smoother surface is not an improvement if the original design language has been erased.
Quick grit logic
- Match abrasive aggressiveness to the visible defect.
- Require a uniform handoff condition before changing stages.
- Choose the final refinement level from the intended coating and sheen.
- Protect geometry throughout the process, not only at the end.
Bottom line
There is no single best grit list for every 3D print. The professional approach is a controlled decision system: read the defect, select the least destructive correction, verify the handoff, and preserve the part's geometry. The complete PolishMaster Formula documents the specific paths separately.