I keep mine in A4 brown paper envelopes - old ones, that I am reusing. I can usually fit ten issues in an envelope, and I write what they are on the outside. It's not a great system, but I don't have the space for anything else right now. I do keep them bagged and boarded, if they came with the board, but I don't buy boards for the boardless. (Whoa, board has just lost all meaning.)