What I remember from art class...
- Wear old clothes (you're going to get splattered too) and cover your work area with newspaper or a drop cloth.
- Hang up your garment, or lay it flat on the floor.
- Dip a brush/coffee stirrer/etc. (anything that has a longish handle and that can hold some liquid on its tip) into the "blood".
- Hold the brush near its tip.
- Tap the brush with short jerking motions close to the "head" (where the blood is). Depending on how close you are to your fabric and how hard you tap the brush, the splatter will be bigger.
- Another way to get bigger splatter marks: dip the end of a drinking straw into the color so it's loaded, then blow it out from the opposite end with a quick puff. This will probably give you some big blobs of color.
- If your color is thinned out, I'd also suggest drizzling it from up high (off a coffee stirrer, etc.). Try a few different methods. I'd test them out on some scrap fabric first, see what effects work best for you.
I don't know how easily the color will wash out. Depends on what you're using, but generally red's a hard color to get out of clothes.
