The "screen" he's using in the video is called a stencil. They're made out out of thin stainless steel. These days they're pretty easy to come by, even for the

The "screen" he's using in the video is called a stencil. They're made out out of thin stainless steel. These days they're pretty easy to come by, even for the hobbyist.[0] [0] https://www.oshstencils.com/ https://www.oshstencils.com/ (one of many hobbyist level examples)