Your prints aren't sticking? Masking tape isn't working? Try this.
I was an amateur, and I couldn’t figure out why my prints weren’t sticking to my print bed. For a while, I panicked, wondering if one of those faulty G-Codes messed up my printer in some irrevocable way. After all, I’d tried (almost) everything: I must have leveled the plate 20 times, cleaned every little component with acetone, and even purchased a roll of blue masking tape to try to help the prints stick.
The first layer never connected properly, sliding around the bed and preferring to stick to the extruder than its intended resting place. The prints came out with unsealed, hollow layers and lots of residue.
I was using Slic3r for a FlashForge Creator Pro. The default filament diameter in Slic3r is 3mm. FFCP prints 1.75mm.
After adjusting my filament diameter option in Slic3r, my prints are sticking to the bed perfectly. I hope this solution works for you, too: I know how frustrating it is to feel that your piece of valuable hardware is broken or damaged, especially when some part of you knows it’s your fault.