Keeping my DVDs upright in sleeves/box until box is full



I want a good archival storage method for my burned data DVDs, have settled on storing them upright in Tyvek CD sleeves in a CD box, this may sound silly but my question is how do I keep the discs in the sleeves upright in the box? I will be gradually filling up the box as I burn/back up my data to DVDs but while it is not full I notice the sleeves can fall/slip back horizontally on their sides in the empty part of the box, & I read that it is best to store the discs upright/vertically. Are there boxes that have something in them that can keep them upright? any suggestions?



How about a paper weight? :wink: