Black backgrounds are easier on the eyes for drafting (and just looking it, IMHO), but are difficult to print, as it wastes a lot of ink. I usually do a quick negative filter in PSP before sending out a CAD sketch so that it can be printed. Sometimes a manual color swap if one of the layers is hard to see.
PSP is one of the apps I have used, and I find it to be simple to use and powerful.
Used Corel Draw back in the 1990's, and dabbled a bit with Photo Shop (too many $$$ for me!).
Got very use to Corel Draw, and used it quite exclusively from 1995 to 2000 or so. Went to PSP by a suggestion from a close contact, and really liked it! (Corel Draw version I had was becoming too antiquated for use with newer image file formats).
Scott
Scott " 35 " Thompson Just Say NO To Green Eggs And Ham!