ForMatter/Finishes/mold_finish/SPI C2 (medium stone, 400-grit)
finish_mold_spi_c2

SPI C2 (medium stone, 400-grit)

mold_finish · matte · SPI C-2, medium-matte mold finish

A 400-grit oilstone polish on the mold cavity. Reads as a stronger matte than C1, hides flow lines completely, common spec for high-volume consumer-goods that don't need a cosmetic sheen.

SPI / SPE finish C2 — 400-grit oilstone polish on tool-steel cavity. Surface roughness Ra ~0.6 µm. Distinguishes from C1 (600-grit, ~0.4 µm) by slightly stronger texture, more directional from the stone polish. All C-series matte. Cheap mold spec; the workhorse texture for the 'invisible' interiors of plastic packaging, container undersides, parts that get printed or labeled rather than displayed bare.

character — stronger matte than C1, mid-tier matte stone.

Finish properties

  • levelmatte
  • subcategorySPI / SPE stone finish — medium
  • Ra (µm)0.6
  • applies topolymer
Produced by processesInjection Molding

Second life

reversibilityzero on the molded part — the mold-cavity surface is transferred at the moment of forming and cannot be undone without re-molding from a different cavity.
blocks substrate recyclingno
renewabilityzero on the existing part; the mold cavity itself can be re-polished or re-textured by the toolmaker for subsequent runs.

SPI / SPE Mold Surface Finish standards (A-1 through D-3); VDI 3400 mold-cavity texture reference plates.

Citations

  • standard · SPI/SPE Mold Finish Standards (Society of the Plastics Industry, AB-3) — C1 / C2 / C3 stone-finish reference.