Hey! Ok so back when I started the scene was still super new ( I think the only DIY blank you could buy was a Munny) and they did a lot of "open call" type shows that anyone with a custom could get into, mainly because the location putting on the show made money off the blanks the artists bought! Once the scene started to really blow up you started to see more closed shows that are invite only for artists they liked or successful ones... as a vinyl artist or regular artist. If you are well known the invites for those just kinda come like any other gallery invite would (I get them just like you said.. "hey, having a show, wana paint this? " lol) but that could have a LOT do to with the locations you deal with and show at. Since I'm kinda a lowbrow artist of sorts (I guess thats what this current scene is called) Vinyl kinda goes hand in hand with my locations, buyers, and such. If you never did a show before, or say are a fine artist that shows in a fancy NY gallery you would not get a vinyl invite XD different scene!

If you are looking to get into shows and are already established as an artist in galleries, the best way would be to express interest to locations that hold the shows (it never hurts to ask!!) or paint up some vinyl to add to your site/portfolio to show curators how you transfer your style to a 3D figure medium. <3 If you are totally new to showing art and really want to get into customs and showing at those particular shows the BEST way to do that is to get painting! Make customs, show them on the forums, send them in to the vinyl blogs, etc. If you have an awesome look the shows often just find you ;)