Bob; My experience has been that ALL manufacturers chips bleed into the plastic flips or vinyl pages in which pvc softeners are present. The soft, pliable flips are o.k. for short term use, but I would not recommend them for long-term use(years).

The non-pvc flips are more brittle, but I see more and more collectors are breaking them in half deliberately and using just half of the flip and not doubling them over. It's more economical this way and takes up less space so that 3-ring album pages don't bulge as much. The disadvantage is that there is no 2x2 pocket for the paper insert on which valuable information is written regarding purchase price; catalog value; catalog number, etc. The old cardboard fold-over holder with the mylar window is probably the safest chip holder to use and information can be written on the white holder as well. The disadvantage is that they need to be stapled shut.... or one can use the self- seal style without the need to staple.