I bought these stackable trays for two reasons: a) I needed something to organize my papers so I could see all my options, and b) someone posted pictures that showed that the trays fit perfectly into an Ikea Expedit storage unit.
I completely cleared out my "craft room", set up the Ikea shelves, put in my newly bought paper trays, organized all my papers, and I am so thrilled with the results. The papers slide in and out with ease, the clear plastic design goes with any decor, and there is room on the top of each stack to sort my large scraps.
I'm glad I bought two sets at once- this ought to last me for quite awhile.
OK, that may be a bit of an overstatement, but it's true about my scrapbooking paper since I got these trays. Over time I've probably tried every possible storage scheme, but this one seems to work. I have always stored my paper by color but more often upright in folders -- not so easy to see what's inside. With these trays it's quite easy to see what you have and get to what you want. And each tray holds quite a bit of paper. I put mine in two stacks of five trays each on a shelf in my crafts closet and that's working out great.
I have two sets of these in the 12x12 size AND the rolling base AND the drawer inserts - outstanding products!! I've had them now for almost 2 years and they have held up beautifully - VERY sturdy. I have my stack of 20 on the rolling base, which makes rearranging my work space easy and makes it super easy to put the whole stack right where I want it when I scrap. I highly recommend the product - it is well worth the money - takes up little space and provides a huge amount of storage in a small space.