Water surface tension is relatively high, far more than the common substrate. Therefore, water - based materials, especially water - based industrial paint, water - based wood paint, the wetting of the substrate is often called the first problem to be solved. Generally speaking, substances that can reduce the surface tension of water-based systems can be used as substrate wetting agents. But some substrates such as plastic itself surface tension is very low, in order to improve the universality of substrate wetting agent, usually as a substrate wetting agent material to reduce the surface tension ability are very strong (25mN/m), generally based on organosilicon compounds. Based on the above characteristics, they can also be used as leveling agents, so the base material wetting agent can be regarded as a kind of silicone leveling agent with special emphasis on wetting performance, and the biggest difference between it and silicone leveling agent is that the base material wetting agent does not provide smoothness. For systems with special requirements for smoothness, some leveling agents with high smoothness can be used.

By adjusting the oleophilic group and molecular weight of the polyether chain segment in the substrate wetting agent, it can also be applied to some advanced oil systems such as light curing, epoxy, etc. But in the advanced solvent system, its ability to reduce the surface tension is usually less than the water system, so it is more to play the role of leveling agent.

Substrate wetting agent can greatly reduce the surface tension, so when applied to water-based systems, it usually has the negative effect of bubble stability, so it is often used with defoamer. However, adjusting the hydrophilicity of polyether in the substrate wetting agent can also obtain unstable bubble products.