"White gesso" refers to a type of paint primer that is white in color. It is used to prepare surfaces, like canvas or wood, before painting to create a smooth and even base for the paint to adhere to. Full definition
Don't Quit Your Day Job: Jeff Koons 2017, Old Holland Ivory Black oil paint on white gesso on wood panel 22 x 36 in / 56 x 91 cm (lyonswiergallery.com)
De Crignis would begin with a smooth white gesso ground, then over weeks add as many as forty layers of semitransparent paint in glazes. (bampfa.org)
Next she added colour, mixing and modulating her own shades of acrylic paint, skilfully diluting and mixing them with chalky white gesso to create luminous, light infused colour. (christies.com)