I don't sell my actual drawings, but rather archival prints of them. That is what I enter into shows and give to clients. Because it is important to me that the print last, I do not use card stock that is "regular". Archival means it won't decompose from the chemicals in the fibers of the paper. It is made to a higher standard than usual heavy weight stock. It is also printed with pigment-based ink rather than dye. Dye will fade away quickly if the piece is hung where there is sunlight and who would want to have purchased a piece that disappears? So the ink and paper that are used are important to me. When you purchase a print the artist should know if it is archival, if they don't, it probably isn't.
Our exhibit at the Museum beginning July 28 we will have two categories... original or archival copy. So if you think about it, sometimes an archival copy could last longer than the original, depending upon what was used by the artist. Some artists don't care and think it frivolous to worry about, but I think those types of artists are not interested in giving their clients the best they have. They are only interested in selling or making a name as an avant-garde type artist.
The important thing is to keep on drawing. Observing life. Getting out there and being one with what is happening where you are at that minute. I you aren't an Urban Sketcher you are welcome to join the USkT (Urban Sketchers Tacoma) on any of our outings. You may find them here or on FB under our name.