I just want the poke dot pattern and I want to know how to make them in gimp maybe. I though people here would know more
But I'll help anyway since I do both.
It's called a halftone pattern.
Make a gradient in photoshop
filter> Pixelate> Halftone screen
Radius to whatever you want.
set the channels all to 0.
I ended up having some weird shit in the middle of my dots after, so just select the negative space, invert selection, and fill the dots with your main color.
You could go the long route as well by converting to grayscale, then bitmap. You get a lot more control that way.