You could lay the quilts ACROSS the top of the bed king size bed. This is what I have done. I bought a king size unquilted bedspread in ivory. (Walmart on line about $40.0 (also painted the walls ivory and have ivory curtains) The quilt tops I make about 70x90 so I lay them across the bed having a drop on 3 sides and quilt not coming up over the pillows. I try to have 8-10" drop which make the quilt big enough to cover us up. By having everthing ivory then I can change the color of the bedroom with different quilts whenever I want. Therefore using all the beautiful quilts I have made. Now our bedroom is lavender and last week it was pink. The bedspread hangs down similiar to dustruffle but you do not have to worry that matress is not covered by quilt. IMHO adding extra border to your already completed quilts is a lot of extra work when my idea is easy and fairly cheap!!!!!