So, I have to admit one of my favorite aspect of Fluxx is the Blanxx, since I love to make custom cards. Admittedly enough, I get it where sometimes I have friends who really want one of my custom cards as well and so I make them one too. However, it often means I have left overs from a pack where I didn't use them as much (for example, I have bought over 10 packs of the newer blanks yet have a ton of rules and creepers but no actions, keepers, or goals left over because I used them all) The older packs were great because they had a decent ratio of how many custom cards are made. Plus, we now have another 2 types of cards (ungoals and surprise) that there are no blanxx for.
What my thought is, although I don't know how feasible it is, but instead of just making mixed packs of blanks, also making multipack of single blank types to purchase. Plus then, if any other demo team members want to, they can borrow the idea I've ran through my head a bunch but backed out of just because of sheer price to get the number I need of a single type of blank, is to make a custom card that could be handed out as prizes for an event.
I'm hoping I'm not toe-ing the line too hard with that idea for copyright issues or whatnot, but I just had a player at the last convention I ran at ask of me "hey do you have any custom cards relating to conventions?" which gave me an awesome idea of making a card that specifies conventions in it.
Just a thought :)
I just inquired about getting just one type of Blanxx myself for a project I've started to expand my Star Fluxx deck. Looney Labs used to offer blank cards by category but apparently it became impractical, so they switched to the variety pack.