Just a stencil taken from a picture. The file seems a little small at 100% but you can adjust it. If you use the picture file in cura, make the lighter higher, make the base close to zero or zero, and then using the Z axis, push it down into the bed to make the holes actually holes.
Or if you know a better way, do it that way. that's just what i did.
Also, i didn't need all the layers. I stopped mid way through printed and it works great.
CCR10_Weathering_Stencil.stl | 103.2MB |