There are plenty of things you can use for filtering out small particles depending on your application but if you're looking for something to filter the water coming from the overflow it's hard to beat a good quality filter sock. I find that alternative products don't last long, are more difficult to change and wind up causing more problems than they are worth but they will get you buy in a pinch. If you make or buy the sock holder it makes changing the socks a breeze. I've heard of low quality socks that fall apart when washed but I've been using the same 2 socks for months, I just toss the used one in the wash and put on the spare. I like the 7" size over the 4" if you have room in your sump because they last a lot longer between changes.
Here is a pic of the sock holder I made for my 7" Diameter socks.