Stampless FDC Cachet Covers

Hey does this qualify as a stampless cover . Seriously, is there anyone out there that collects FDC cachet covers that are without stamps, or are they just another envelope?

I would think that without a stamp or a cancel they would just be another envelope.

However, having said that if the cachet design does not state a specific FD issue and is generic enough it could be used for a current FD cover of a stamp along that same topical theme. For instance, I collect Abraham Lincoln and occassionally run across an unused cachet cover that I would use for a pictorial postmark request. With the upcoming Civil War anniversary I'd be interested in prior civil war cachets.

Thanks stamperdude, great idea!