I've got a Creality CR10-S5 (510mm x 510mm Print bed), and I'm trying to print a large briefcase lid, having had no success at first, the lid kept detaching itself from the glass print bed, after a few months it was suggested that the heater plate was too small at 310mm x 310mm, I removed this and replaced it with a 510mm x 510mm Silicon Heater (240Vac x 1300W), this allowed me to print the lid onto the GLASS printer bed using 3DLAC without it becoming detached from the print bed, but the finish of the surface was too glossy, so it was suggested that I try the Prima Creator FlexPlate Podwer Coated with PEI ULTem (Polyetherimide), the Flexible plate comes in two pieces, the sticky magnetic portion is stuck to the print bed, then the upper portion is placed onto of that, the question I'm asking is do I stick the magnetic portion to the metal bed, or the glass bed? Anyone have any ideas, many thanks.