Storing ULF negatives

What do you guys use to store & index your ULF negatives ?

I've just finished processing my first few sheets, and Printfile sleeves of the right size are not available over here - Perhaps a large box file with folded sheets of acid free paper is the way to go.

This guy has nice clear ULF envelopes with a tab. http://www.climaxphoto.com/store/wide_format_sleeves.htm

Just received my first order of 10x12 negative sleeves from him. As 10x12 boxes are pretty well non existent in the US I'm currently storing my stack of negatives in 11x14 boxes.

This place is in the UK and might have something that will work: http://www.conservation-resources.co.uk

The clear negative sleeves are nice because you can see and handle the negatives, but the folded archival paper is easier to get the negatives in and out while you're printing. It's a toss up. I think I'll eventually put the negatives I want to print regularly in the paper and the others in the plastic.

There are some threads on this topic on the Large Format Board as well.

I use Itoya Art Portfolios--they're archival, inexpensive, and work very well for organizing negatives.