How can I prevent pinholes and fisheyes?
You can do four things to prevent getting pesky pinholes or fisheyes.
1. Clean your darkroom. Keep floors, surfaces, and fans dust-free. If it's difficult to keep dust and debris off screens, buy or build a screen drying cabinet so screens don't get dusty.
2. Clean your exposure unit. The glass on your exposure unit will get dirty with use. Fingerprints, dust, dirt, and adhesive can block the light from the exposure unit. Use a glass cleaner and a rag to remove any debris.
3. Degrease screens. Degreasing removes any oils, dust, and dirt from the mesh, all of which can cause issues in the adhesion of your emulsion.
4. Use soft or hard water filters on your hose. Hard or soft water residue can cause issues with emulsion sticking to a screen. Mineral deposits left on the mesh can lead to pinholes and issues with durability. Find out whether your tap is hard or soft and pick up a filter to minimize the mineral deposits.
To learn more about preventing pinholes, watch this video.