I agree with amo and peter’s advice.
As for the paper, I use 20# general purpose office paper. I bring the nozzle down to the paper, and pull on the paper. It should glide across the nozzle with modest resistance… leaving an indentation trail – but only just. If it isn’t leaving an impression on the paper, its probably too loose. If you find that you have to really pull hard, you hear paper fibers crackling, or the paper rips (obviously) or it is carving out a ravine into the paper, then it is too close to the bed. Move in .05mm increments when calibrating.
Your first layer of plastic should look pretty even across the bed. If there are areas that are not getting plastic, or it looks patchy or thin, then those parts of the bed are too close to the nozzle. If you find that the plastic is dropping onto the bed on the first layer (even a little), then the nozzle is too high (bed is too low) in that area. The nozzle should be lightly pressing the plastic directly onto the bed with no drop, like a bead of caulk or frosting from a baker’s bag. If the plastic has to drop onto the bed, then it won’t stick, because it starts to harden before it hits the bed, and the bed isn’t hot enough to soften plastic that is rigid, or even near rigid.
But I have to say for the record, I have not had any issues whatsoever with prints not sticking. I triple check my leveling (backwards and forward), and put my first print layer at 55 degrees – and have never had an issue with it peeling off early, or not sticking. I’ve not needed to resort to glue stick, blue tape, abs slurry or any other techniques. Just the SnapMaker sticker. I wipe down with alcohol after a print, but that’s it. Even with my one newbie attempt with ABS, the first layer stuck like a dream.
So, it makes me wonder… if you are positive that you have leveled correctly, and you are certain your bed is fully up to temp, then I wonder if something might be wrong with the unit.
Have you tried using a raft? Or at least a brim? I’m a big fan of rafts because the bottom part of the actual print comes out so beautifully when I use a raft. No weird texture, and it releases easily. But, a raft will give you a nice big surface area to increase opportunity of cling, and it will also help address any minute leveling issues that might exist that are beyond human correction.
I also recommend starting with small prints first, like 5 cubic cm. Get that down consistently, then step up the volume. Watch your first layers closely. Don’t leave the room until you get a few layers down. Stop the print if it begins to peel. A first layer that isn’t sticking at the beginning, will not change its mind later.
Stick with it Patch. Have fun!