Creep N' Crawl is a very high performance 1-time permanent cavity wax. Applying Cavity wax from a bulk container is much less expensive than using solvent based producyts in aerosol spray cans. What does "100% solids" mean ? When a coating is chemically "100% solids", what you pay for is what you'll end up with. But if the product is only 50% solids, then the other 1/2 is "fillers" (water, solvents, etc.) is going to evaporate. Fillers are not a bad thing. They are often needed to hold the cost down. Naturally formulas that have no fillers (100% solids) are more expensive, but go much farther in coverage because you are using much less. What you spray wet, is what you are left with dry when using a 100% solids formula. If the coating is any less than 100% solids the thickness of the coating will decrease because any additive (solvent, water, etc.) that is not a solid must evaporate during the drying process.