“Styro” is a slang in the self-harm community referring to cuts penetrating down to the second layer of skin/ the second layer of skin itself, the dermis (which is below the epidermis, and above the hypodermis), called Styro because it looks white for a second or two after you cut, followed by blood flooding in. Styro cuts will often fray at the edges, and be slightly wider at the center than the ends. Styro cuts will often not fully close until a week or so after cutting (at least when bandaged tightly & disinfected), and are known to leave faint permanent scarring. There also exist slang terms referring to cuts to the epidermis (baby cuts/ cat scratches, as many feel that they themselves aren't valid because their cuts do not go as deep as some other people who self-harm), and slang terms referring to cuts to the hypodermis & attempts to cut down to it (those terms being “gold” / “beans” for the higher up layer of the hypodermis, called such as it’s composed of uneven, yellowish fat, with a texture reminiscent of beans, “mining for gold” for attempts to cut down to beans, and “taffy” for the layer of muscle below the fat).

It is also worth noting that self-harm is addictive, similar to nicotine, and you should not ever consider starting. Despite the fact that the concept of being miserable may sound strangely appealing, four months in when you actually are miserable, it looses its magic.

See also:

self-harm
self-harm_scars