The use of an over mat that is attached to the backing board with tape and hinges upward provides a different aesthetic. The mat has a window cut through it to view the print that creates a sense of depth. Not only can this provide an additional aesthetic frame for the image but it also creates a physical gap between the print and any glass that might be in front of it which allows the work to breath. In limited environments placing any print directly onto glass can work in some situations for a short period of time, but there is the risk of humidity sticking the print to the glass and totally ruining the work.