craftgrrl | question about those luverly marble magnets

So I went on the Hunt for Marble Magnets this week -- caving into the trend, and all that :)

First went to Ben Franklin. All they had were itty bitty flat backed marbles (maybe a 1/2 in at best, and that might be a generous estimate) and ones that were about 1.3 inches wide that weren't very round at all. I bought the bigger ones, but they were too big for the magnets I have.

(I did find some great hi-strength magnets there, at least, for about $1.99.)

So next stop was Michael's -- same thing there! either really small (and irridescent to boot) or ones that were about 1 inch or so. Those worked better than the Ben Franklin ones because they were 1)actually round and 2)smaller enough to almost fit the magnets.

This leads to my main question -- how big are the ones that people are finding and having success with??! If it's the smaller size, how in the world are you finding pictures that fit?