Well, a while back I posted a sort of tutorial with pictures of the results of spraying discs. I can't seem to find it anymore. Anyway, it is possible to get the spray on the data side if you use too much spray. However, I think common sense would kick in with most people before it reached that point. You're not looking to pool the spray on the disc, just several light passes to give thin, light, and even coverage. I always spray my discs on top of non-glossy newspaper (outside for ventilation, too). It absorbs some of the overspray. I've probably sprayed 500 discs and never had a problem. They look SO much better.