Liquid coating refers to the most traditional finishing application of wet paint. There are still many uses for wet spray: fancy finish colors unable to be reach via powder coating (like for autobody), specific texture patterns unique to paint, soft suede finishes, wood coatings, plastic coatings, and other non-bakable material finishes.
Part cleaning is only the first important step to proper finishing technique; pretreatment is the critical step for paint adhesion & corrosion resistance. The cleaning process removes oils, soils & other contaminants from the surface, providing a fresh substrate to deposit a pretreatment foundation for paint to adhere to.
Silk screening, or more commonly known these days as Screen Process Printing, is a clear & concise part marking process where ink is applied through a emulsion filled screen onto a clean non-recessed surface.