Now for the fun part (okay I know I am a bit of a sicko here)

Let's play with the microballoons

I use 3M Micro Bubbles available from Aircraft Spruce - I've used the Top Flight product before and these just seem like a higher quality product. It might be exactly the same but I can buy a 1 lb sack for the same price you can get the little Top Flight bottle at your LHS. Yea, this might be a life time supply for the average modeler, I think I paid less than 10 bucks for this sack.