Guys, I am accepted as audio contributor today. But I have problems with illustrations. Can someone help me? Can someone give me quick guidelines what I can use in my illustrations and what I can't? For example, can I use svg filters like gaussian blur for example if opacity of my layer is 100% etc.. I know I can't use transparency, but what I can use to simulate it? Maybe some gradient to match wanted colors to simulate transparency. Can someone give me some link wher eI can read it? Something more explanatory than "quick guidelines" from IS.
Thank you in advance!

This might be of interest:
http://www.istockphoto.com/forum_messages.php?threadid=75477&page=1

Not sure if this helps, but these are the files that got me accepted as a vector illustrator at iStockphoto:

IMO opinion IS values originality and virtuosity much more than any other site and values an image's commercial potential the least. So submit your most technically impressive work as opposed to your most commercial work. And avoid images which are similar to those which IS already has.

Merry Christmas and good luck!