I've seen quite a few recommendations from people that, after you have applied the thermal paste to your cpu and mounted the heatsink, you should remove it and check the imprint of the paste to make sure you have enough coverage.
I have always taken that to be a method to get a representitive idea of spread, a reapplication would follow.
Wouldn't this completely negate the purpose of the TIM? The whole point is trying to minimize air pockets, so when you mount the heatsink the first time the action of the TIM spreading pushes out all the air. But if you REMOVE the heatsink and then plop it right back on, the two layers of TIM will trap air when they come back together, with nothing to push the air out.
Yes it would - I wouldn't do that