i use a heavy weight paper as a gauge .1 mm thick . I set it so it has a slight drag and it works great . I recently replaced my heater pad with a larger one from Ebay
Seller solidset
Solidoodle 3 Replacement Silicone HeatPad HeatBed 200mm x 200mm or 8" x 8"
( 191285757844 ) .
Pulls twice the current , heats the bed up in 1/3 the time the original did , heats the bed area more evenly then the original . Cost was about $21. DOES REQUIRE!!!!!!! a relay hooked to original board pins , and i used a more powerful 20 Amp power supply . I had had many sticking problems before I did this upgrade. I tried every solution offered ,ABS glue ,glue sticks (5 different brands) ,sand blasted glass, painters tape , hairspray , added brims to prints ,all kinds of temp settings I tried them all . I did this upgrade went back to simple glass bed with cheap hairspray and add a 4 mm brim to all my prints and went from 60 % failure to stick rate to less than 5% ( usually if I get lazy and don't respray after 2 prints in same area it will lift a corner or 2 ). Hope this helps it worked great for me. Bill D
SD3, RAMPS 1.4, Lawsy's carriages modified by me, 2 SSRs, E3D V6, 2 Power supplies, Independent monitoring of both power supplies (amps and volts) also extruder and bed temps, Blue Tooth connectivity, bearings in all axis & rotational points, Y axis direct drive. Remotely controlled power box on / off . Gecko Tec build plate . Renamed FrankenDoodle