I buy from Kinkos/stationery stores
the bordered invitation or double card with perforation. I found though that ink jet printing fades in a few years on cheap paper, so I buy good card stock.
I have Kinko's color copy on their laser copier the design with borders (I do it two to four card or more to a page). It's not cheap, but the card will last and the color will not fade.
Mari H.