There are a few options to address this but none have been taken. The easiest would be removing the color, type, and stat bonuses from tarps and just leaving quality and durability, making them all stackable (just like leather straps).
Another option is create some way to make generic cloth. Basically combining any types of cloth together into a cloth type that is a neutral color and has only quality and durability stats. SWG had reprocessors that you could throw different types of materials into and it would all convert into a single item with a static set of stats, 200 on all stats, I believe, regardless of the stats on the mats you put in (this helped on the DB side as well, as all reprocessed stacks were instances of a single object)