DJ's Shadowkit is on sale for $199 - can be useful to have in your arsenal. I have used it - easy and fast to set up. You can make your own, by for example cutting patterns in foam board, but the DJ kit breaks down and rolls up so it's easier to transport. The cost for commercially available flexible cucoloris patterns add up pretty fast (f.ex. on B&H), so the DJ Shadowkit is economical at this price, if you ever use this kind of light modifier.