Reddit reviews eHomeA2Z Foam Paint Brush Value Pack Lightweight, Great for Acrylics, Stains, Varnishes, Crafts, Art (20)

So these are some of my earlier ones, and I've improved my process a lot while making them. I'll post my next batch in a few days, it's noticeable how much cleaner they are.

I'm working on some super-basic black cotton fabric I got at a craft store. I just picked out something thin and not-stretchy. All color is applied with liquitex acrylic paint. Other than that you'd need a craft knife, scissors, push pins (thumbtacks), paint brushes, foam brushes, and your patch designs printed onto paper.

First, I cut the patch shape out of the fabric, and paint the entire surface black with a wide brush. This evens out the gradient of the fabric, gives you a much nicer surface to paint on, and seals the edges against fraying.

While this dries, I cut the stencil with a sharp craft knife and affix it to the painted fabric. I use push-pins for this, but if you'd mind the holes, temporary adhesive spray would probably also work.

I apply the first coat of un-thinned paint with a foam brush. Just load the foam brush up and press firmly straight down onto the stencil. Between the foam brush and tacking the stencil down, I've been able to get a very sharp first coat that requires minimal touchups.

Let the design dry a bit, then touch up the edges with black and white paint as needed, applied with a normal paint brush. Let dry, and (optional) spray it with an acrylic sealant and you're good to go.