I used a product called Maxikote on my drywall 15 yrs ago. I got a beautiful smoothe plaster finish. It even whet over a plywood patch that was made. I want to do another room but the product is no longer available from El Rey Stucco. Does anyone know of a similar multi purpose plaster product I can use on drywall to get the same smooth plaster finish? All help and advice appreciated.

Thanks.

You are describing "Veneer Plaster" which is a plaster skim coat. A couple brands I know of are Kal-Kote http://www.gypsumtoday.com/library/productfocus/national_gypsum/NGC_Veneer.pdf
and USG: http://www.usg.com/USG_Marketing_Content/usg.com/web_files/Documents/Installation_and_Appl_Guides/USGNorfolkSpecialVeneer_Plaster-Installation_Guide.pdf

There are other similar brands. Hope this helps.