A section of cardboard is varnished with 'Liquitex'. After drying, the varnished side and appropriate water color paper (smooth side) are sprayed with "Loctite" adhesive and, after waiting one minute, bonded together.
The watercolor paper is given two coats of gesso and no curling is observed. I still place the platform under some weight for 1-2 hrs before using. It is ready for oil painting studies or small-scale permanent artwork.