Then there are proofs called Collaborator Proofs
(noted as: C/P). Often times in work with sculpture, several
people will be employed such as the patina artist.  This
artist, working as a collaborator, may receive several pieces
to test the patina's on.  This addition to the edition will
range from 5-10% of the edition size.
Finally this brings us to what is called "Hors de
C o m m e r c e , " which are proofs given to art galleries for
window display as a way of promoting the artwork itself.
Some artists in today's market use these in adjunct to their
selection of limited editions.
Most artists charge a premium for the adjunct
editions. The reason being, each edition size of the adjunct
types is much smaller than the main edition. Therefore if
there are only 10 prints in an adjunct edition they
should be worth more than a print from the main
edition. Some artists will enhance or hand-embellish proofs
to back up the increase in value. If an artist normally does
hand embellishing in the main edition, they will do extra
hand embellishing on the proof. Some artists will choose to
do a re-mark . A re-mark is a small original sketch or
drawing done either on the piece itself or just below where it
ends and open canvas begins.  This is a special way of
boosting the value of the adjunct editions.
It's always important to understand what you're
purchasing.  Is it the standard type edition?  Is it the
printer's proof? Is it an artist's proof? In general you should
really judge for yourself how having one of these editions vs.
having a regular edition would psychologically make you
feel. Because there is really no rule within the art industry
itself stipulating what an artist should charge; the bottom-
line question often is, whether or not you believe you
got a the right deal for your money.  There are a
percentage of artists who place no higher value on adjunct