Screen filler is supposed to be applied with one sweep of the squeegee across the screen. So I dribbled a bead of screen filler across the top of the screen and used my squeegee to pull it across the screen. I worked great - but I didn't believe that could possibly be enough and without thinking I pulled the squeege across the screen again and this time didn't apply even pressure, as you can see in the photo. Next time I am going to have to remind myself to stop after the first time. I think I was just so excited to use the squeegee that I couldn't stop myself having a second swipe at it!
Nevermind. I left the screen to dry overnight and washed it out in the morning. This is when I really regretted that second swipe of the squeegee. The areas that were lightly covered with screen filler washed out quickly, cleanly and easily. The areas where the screen filler was more thickly applied took a lot more effort. I really had to blast the screen from both sides with cold water from the shower head. I also took a cotton bud and had a little rub in some areas. Even after that there are still little specks of filler in some places.
The blast with the shower head also loosened some screen filler in the areas where I wanted screen filler. So I took my paintbrush and reapplied screen filler to those areas.
Now I am waiting for it to dry again before printing.
Celestina Carmen - Detailed explanation of using drawing fluid and screen filler. Mon lapin - Step by step guide to using drawing fluid and screen filler. Lena Corwin - Printing by Hand: A Modern Guide to Printing with Handmade Stamps, Stencils, and Silk Screens