Stephen, you must use a release material, either release paper or release board, to prevent sticking the exposed area of the pre-adhesive board to the lid of your press.
MountCor by Gilman Brothers is a popular choice, which has a thermosetting adhesive. That is, the application of heat activates the bond and it is permanent. If the item ever needs to be removed, such as when a mounting mistake happens, solvent removal is the only choice.
Kool Tack is another popular product, which has a thermoplastic adhesive. The application of heat activates the bond, but it can be reactivated with subsequent application of heat. So, if the item ever needs to be removed, you can do it using heat, which is less messy, less invasive, and less costly in time and materials than using solvent.