Halo around washes

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If you are using an oil-based wash, you can minimise the formation of "tide marks" by wetting down the area slightly with clean thinner before applying the wash.

If you are using acrylics for the wash, I found it works to dampen a small paint brush, and sort of  stroke and feather at the halo until it disappears.  For stubborn situations, dampen the brush with windex or other proprietary window cleaner.  

Don't let the wash sit too long, or it will become unremovable by any means or methods.

Good luck with it.

try using a q-tip and the thinner for the wash to remove it.  If you apply the wash over a gloss surface, this shouldn't happen.