First Layer, Flow, Calibration, Temp, Speed, Adhesion Test

A little on my take on the whole bed gap (bed leveling).

It can also be done hot but its just safer and easier while its cold. There is really not going to be a "set" standard on what size feeler gauge to use and even with paper everyone has a different "tension" they feel and gotten used to. You can use another's as a starting point and work from there. When the machine is cold you place a gap between your bed and the nozzle. Heat makes things expand! So your print bed and the glass will expand upwards as well as your extruder and nozzle will expand downwards. So once things are properly preheated they "should" touch. Which is what should happen because that's where the printer thinks zero is. On the bed. So when your printer moves up to say the .2mm of your initial layer height, the print head will physically be .2mm above your bed.

If you gap your bed wrong - say for a second you used .1mm to thick of a method - Now when everything preheats and expands, the print head is no l