Here are a couple of helpful ideas for making a mask 1. Use generator to make mask pattern. 2. Print on transparency film for laser printers. Works for scopes up to @ 8" 3. Cutout pattern with Exacto knife and steel ruler using a piece of glass for cutting surface. (No grain lines to grab blade) 4. Cutout a circle in a piece of 3/4 pink/blue/yellow foam about a 1 inch larger in diameter than your scope, then cutout scope diameter. This will look like a donut. It does not have to fit tight on scope. 5. Paint your pattern with flat black paint. 6. Tape or glue the pattern to the foam. This mask will not scratch scope and it weights almost nothing. Works really good.