I have found this old card of black plastic buttons with the insignia of the RAF. I have only seen issue buttons in brass or gold colors. Any ideas of what the purpose of these buttons would have been?

A number of these buttons have turned up here and there, in white, and also bright electric blue. No one has ever been able to put a pinpoint on what exactly they are, but thankfully you have the card as well, which leads me to believe (and something which is probably the concensus of opinion anyway) that they are a novelty item, the sort of thing you could purchase for childrens outfits and the like.

That was my feeling as well, but they were cheap enough that it was worth picking them up just for the fun of researching them.

I have seen and noted various styes of "private purchase" type RAF buttons and my summation is they were aimed at the distinguished gent wanting to customise his civillian blazer or jacket etc.