I've made my own clear album and I used ordinary transparencies. It was not that stable, so I had to work out a design which supported the clear pages. You can find my album here if you want to take a look: Clear album BUT!!! When I do my next one (they are addictive...) I'll use Hambly overlay. I just did a clear card and it turned out really great. More clear, more stable, easier to stamp on etc. clear card
I have made my own clear albums before. I went to Lowes and bought a sheet of acetate (like plexiglas, but thicker), then used a box knife to cut out measured squares for my pages. I got 8 6x6 pages out of 1 sheet of the clear acetate, and cost me about $8.00.