While there seem to be different uses of the term Plastikote, here is a trademark filing for this graphic logo from 1946.
Registration Number: 0565437
Word Mark: PLASTI-KOTE
Status: 900 - Expired
Status Date: 2003-07-26
Filing Date: 1946-10-23
Registration Number: 0565437
Registration Date: 1952-10-21
First Use Anywhere Date: 1941-02-01
First Use In Commerce Date: 1941-02-01
Goods and Services: READY MIXED PAINTS, PAINT ENAMELS AND VARNISHES FOR APPLICATION TO INTERIOR WALLS AND CEILINGS, WALLPAPER AND EXTERIOR WALLS OF WOOD, STUCCO, BRICK OR SHINGLE
more info:
https://trademarks.justia.com/715/11/plasti-kote-71511352.html