Why to use the single layer and multi layer filter mesh? It is ultimately determined by the material and particles you’re filtering.
if you are filtering a liquid with contaminant particles of variating sizes, you may benefit from using a multi-layer as the larger contaminants would potentially damage the mesh and significantly reduce its accuracy.
If you are filtering a liquid with minimal non-abrasive impurities or attempting to extract a filter cake, a single layer configuration may be suitable for you.