No. I painted the glass with black acrylic, gave it 2 coats. After that was dry, I used the adhesive that came with the flock-it kit then used their “mini flocker” to flick the flock onto the sticky stuff. When I tried using just the adhesive on the glass, with no (dry) paint under it, there were see-through gaps. The layers of (dry) paint hide those gaps. That problem was probably specific to glass. I bet using just the adhesive on wood will be fine.
[and, just fyi, I’m a “she” 
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