I use several types of pages depending on what I am doing with my patches and the overall value of them.
For my traders, number collection, and a few other small collections, I use Ultra Pro pages. Depending on the size of the patch(es), I use one of the following sizes:
6 Pocket Pages: These are used for most all of my regular sized Flaps and CSPs. If you slip a piece of card stock in each slot, you can fit a total of 12 patches per sheet. Here is a link to purchase: http://www.cardsnetwork.com/ultrapro-pocket-platinum-pages-tall-cards-p-259.html
2 Pocket Pages: These are used for most of my 2-piece items and other things that just won't fit into the 6 Pocket Pages. I use card stock on these as well to make everything look nice. Here is a link to purchase: http://www.cardsnetwork.com/ultrapro-pocket-platinum-pages-photos-p-264.html
1 Pocket Pages: These are for my back patches and other things that will still fit in a binder, but won't fit in the 2 Pocket Pages. I also use these when I want to display several patches together, like a small Jambo set. Don't forget to put a sheet of card stock in to make everything look nice. Here is a link to purchase: http://www.cardsnetwork.com/ultrapro-pocket-platinum-pages-8x10-photos-p-262.html
For my home council and lodge collection, I use slightly more expensive sheets. They are quite a bit thicker and there are 2 layers of plastic between the patch and the outside world. Depending on the size of the patch(es), I use one of the following sizes:
Stage I: These are for the regular and slightly oversized flaps and CSPs. Smaller odd shapes also will usually fit in one of these. The unique thing about them is that they are basically a plastic envelope that goes around the patch, and then that is put into an album sheet made from the same material. Each "envelope" also comes with a piece of card stock with a section designed to catalogue the patch.
Stage II: These are for the 2-piece items and other things that won't fit into the stage I. Again, one needs to purchase the "envelope" and the album sheet.
Here is a link for the Stage I and II protectors: http://www.oapatch.com/pps.shtml
Just as a note, I'm sure that you can find many similar items when searching through the internet. I provided the links because that is where I usually purchase from. I am not affiliated in any way with any of the sites above, nor do I get any sort of profit if you purchase anything from them (although that would be nice).