stencil brush
A brush used in stencil printing or dyeing to push pigment through a stencil. Domain-specific art term.
In stencil dyeing, you use a stencil brush to work the dye into the fabric.
Compound of 刷り込み (suri-komi, 'rubbing in') + 刷毛 (hake, 'brush'). The exact historical derivation is uncertain, but the term describes the tool's function.