12 Stencils and the “T”
Stencils are a great way to add transparency to multiple layers. And then there’s that “T” switch…
The previous chapter was devoted to Track Mattes: having one layer create transparency for one other layer. Stencils, however, create transparency for all layers underneath. You can use a layer’s luminance or alpha channel as a stencil, and invert it as well. This chapter also covers the Preserve Transparency switch, and an obscure but useful mode called Alpha Add.
Three layers have been blended with blending modes (left) with a matte (center) placed on top; this will become the alpha channel for all underlying layers when it’s set to Stencil Luma (right). Background movies courtesy Artbeats/Digidelic and Starfields.