Talk:Heated Bed Insulation
I too think it's a good idea to use some kind of thermal insulation under the heatbed. I noticed that the MK2B heatbed I am using can easily reach 60C or 65C when printing PLA, but it's an entirely different story trying to reach 100C when printing ABS (I am using a 12V power supply and RAMPS electronics).
I am going to try the cork sheet method and will report here on how much of a difference that makes.