When you’ve unboxed your brand new 3D printer all you want to do is plug it in and start printing some cool stuff. Unfortunately many hobbyists are discovering a problem when they first try to print in PLA plastic. The first layer of the melted PLA will not stick to the build platform.
Many entry-level home 3D printers, such as the Printrbot, RepRap and Solidoodle, cover the build platform with Kapton tape but its performance degrades with each successive print. Replacing the tape starts to get expensive and so a guy called Chris experimented and discovered that hairspray provides the adhesion that is needed. He advises that the build platform should be coated with the hairspray before it is heated so as to avoid any risk of ignition.
He also discovered that a solution of ABS and acetone wiped on the platform before heating worked, but not quite as well as the hairspray. Other methods that have been suggested to work are using a glue stick or a weak solution of PVA glue and water wiped over the platform.