Thanks everyone for the tips. I had thought of DIY, Ivanhoe, but I'm awful at it! I had tried just to stick them up on the wall with some double-sided tape, but they fell off, hence the need for a frame!
I kept out of this one because I didn't want to put you off having a go, but based on personal experience I'd advise against trying to make them yourself. They look deceptively simple but it takes the right tools to do a good job and yes, they'll not be cheap to frame. I imagine Dyson would be a bit expensive, good guys but they work with all the contemporary galleries in London and have prices to match.