Original sentence: Stamp issues may be distinguished in catalogs based on the presence or absence of burelage as well as variations in the burelage itself, such as the size of network,   orientation on the stamp,   color,  or method of printing
Edited sentence: Stamp varities may be distinguished in catalogs based on the presence or absence of burelage as well as variations in the burelage itself, such as the size of network,   orientation on the stamp,   color,  or method of printing