Help with aquarium background
Plastidip is a rubberized plastic compound in an aerosol. It's not paint. It dries like plastic. Sprays on thick and bubbly, but dries smooth. For best results, do it in low humidity, no direct sunlight, and spray in on a horizontal surface. Just lay the tank down if you can. Prevents dripping and runs. If you can spray horizontally, spray on light coats.
I usually do around 5 to 6 coats. I spray the first one on pretty thick and even coverage. Then I just wait until each layer gets tacky and spray again. Usually gets to that point after about 15 to 20 min. Spray on as many coats as you want. It will only make it more durable. You will be able to see any spots you missed due to how black it is and the light showing through. I would say that it is dry to the touch after a few hours. I'd give it 24 hours to be completely dry. Do all your drilling before you use it though. If you try to drill through it, it will just shred the area around it and it won't look nice.