A Person who will borrow a new issue of a magazine from someone, and proceed to curve the first few pages around the back cover, to allow one handed reading.
This creates an ugly crease along the spine of the magazine, detracting from its new magazine appeal.
Spine breaking also occurs when a person sits the magazine on a table and applys weight, so it lies flat. This is a more severe, but rarer form of spine breaking.
Spine Breaking is more common amongst Men, who are usually pre-occupied with the other hand. Spine breaking does not discriminate between magazines, however Mens Health magazines are more likely to be shared, and therefore exposed to spine breakers.
Spine Breaking is the pet hate of Magazine collectors, who will prefer to read their new issue wearing gloves and resting the magazine in a library book to attain a healthy spine
Spine Breaking can also occur institutionally, when magazines and books are scanned/photocopied for referencing.
A broken spine is usually a series of bumpy lines where the glossy layer of paper is broken, revealing less attractive paper.