PEI Ultem (Polyetherimide) is a reusable, relatively maintenance free, build surface for both ABS (with a Heated bed) and PLA (hot or cold), other materials such as Metal, Wood, PETG, ABS+ and many others also works just fine. You don’t require any additional adhesives such as glue or tape. PEI is appealing due to its "no-surface-prep" conditions, which make it convenient to work with. Additionally, printing on PEI requires no support rafts as parts adhere directly to the surface with no issue.

How To Use.
PEI is easily cut to size by scoring with a hobby knife. Once you have laminated your sheet of PEI onto your glass, simply re-level your print bed and print away. Parts should come free from the surface with almost no issue at all. PLA does not require heat, but turning the heated bed up to 45C helps. After the print is done, just let the plate cool down and then gently you can just “pop” the model off the plate.