Cutting blackout plastic
I've almost got my darkroom finally set up, but I'm a bit stumped on this. I have the Delta Black Out Cloth to cover up a bathroom window, but I'm unsure of the best way to cut it. I've tried scissors, but they aren't strong enough. So at this point I don't know what I should use to cut out the right section of plastic.
You will need to buy some heavy duty fabric shears...(expensive!)
Try going to a home improvement store and buying something like a carpet cutter. This might work just as well.
Depending on how thick the plastic is (and this method isn't suitable for something more than 1-1.5mm thick), a No. 23 blade on No. 4 scalpel handle (load blades with pliers, not your fingers!). Fetch a true-steel-guided edgeT-section ruler (to keep your fingers away from you-know-what). It works, but it's mightily scary... :) Probably best, though, to practice a few times on something before committing to the important stuff!
A utility knife, available in any hardware store, works just fine. Cheap too. Use a straightedge as a guide.