This is a Decalcas Black decal with a small textured pattern, designed to give a slightly rough finish to the parts where it is applied.

 

Additional details for the Texturized pattern - type 1 - Soft decals:

Manufactured by Decalcas in 1/20 scale (also valid for 1/16, 1/12, 1/9, 1/8 and 1/6) with reference DCL-PAT011.

Includes water slide decals.