Derivan Gesso is a great low cost primer for canvas, board or even paper.
The strong white ground gives an excellent tooth for easy paint manipulation.
Being a water-based product, Derivan Gesso can be thinned down with water if desired. If working on canvas, Derivan Gesso will tighten the canvas when dry giving a taut ground on which to paint.
Derivan Gesso can be used to paint over old acrylic works to give the artist a like new surface to paint on. If more than one coat is desired, then it is advisable to sand lightly between coats to obtain a smooth finish.