this is what I read

http://es.wikipedia.org/wiki/Tipo_de_letra

Confidence as high as it can be starting from what we have here. I'm taking tipo as a possible wordplay/double meaning on tipo as type, the medium he works in, and tipo as guy, bloke, fellow, the artist who is doing the creative work.
It could be letting the type go (in the sense of allowing the artwork to flow), leaving the typical behind, it could be approximately 7,349 different variations and combinations of any number of things.
Only Parrot knows for sure because only she/he has the full text and knows the general thrust the translation will take.
I'll just introduce the wordplay element into the equation.

Let me say at once that (1) this is not just difficult; it's impossible; and (2) my answer is frankly pretty arbitrary. But still...

It's a play on words all right. Obviously one of the terms is "tipo de letra", the printed type or characters this artist works with. The other is the expression "dejarse el tipo" itself. This seems to mean "to give your all".

The DRAE lists the expression " jugarse el tipo", defining it thus:
"1. loc. verb. coloq. Exponer la integridad corporal o la vida en un peligro."
http://buscon.rae.es/draeI/SrvltGUIBusUsual?TIPO_HTML=2&TIPO...

It would seem that the basic meaning of "tipo" here is more or less related to the DRAE's 7th meaning: "Figura o talle de una persona", and by extension, the physical integrity of one's person.

From the contexts in which I find it used, "dejarse el tipo" means something similar, used metaphorically. Many of the uses are in football, a rich breeding ground for overblown clichés:

"Un abrazo y a dejarse el tipo por el betis"
http://beticos.alfinaldelapalmera.com/profiles/blogs/para-ti...

"gracias a los 11 que jugaron hasta dejarse el tipo" (on Osasuna avoiding relegation)
http://app.marca.com/Servicios/ComentariosNoticias/Controlad...

"más bien en lo que pensarán estos jugadores es en no dejarse el tipo sobre el abundante césped verde para poder trabajar al día siguiente"
http://www.elrecord.net/noticia.php?id=1019

This last one sounds a bit drastic...

But all this is irrelevant to the task of translation, since there is no possible way of capturing this particular pun in English, and in any case, in the context of an essay about this artist, it's not clear that the colloquial meaning of "dejarse el tipo" is all that vital, except in the general sense of implying total commitment and sacrifice on the artist's part. Frankly it's one of those arbitrary puns just designed to grab the reader and perhaps momentarily amuse him/her.

So my thoughts turn to producing this kind of effect, though not this specific effect, in English with a pun on type. The one I've proposed was actually suggested by the beginning of the text in Parrot's link, which is about departing from type and then returning to it, in a sense:

"La obra plástica de ___________ parte de la escritura, regresa a ella y en este proceso la palabra escrita resurge cargada de valor icónico tras haber sido privada del representativo."

This one seems to be a game anyone can play! My weak pun is based on the abstract below.