Thought this might help you out a bit. I recently found the shelf liners in a 20 inch wide length. Not sure if this helps you at all, not sure how large your cages are. On my 4x2 I cut 6 inches off of one of the 20 inch rolls and over lap if I need two pieces, and I got another perfect one the size of my glass 18 inch wide tanks so nothing goes to waste. Just thought this web site might help you find them in the larger sizes, or in your area. I know you use plastic table cloths, but I just like these cause they always lay flat and no bugs get under.
www.duckproducts.com Make sure you look at the ones without the holes. Copy and paste this url to go straight to the product. This site gives you stores in your area that carry them.
http://www.duckproducts.com/products/detail.asp?catid=5&subid=24&plid=105
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Mystical Dragons



