Thixotropic materials are those who stiffness can be reduced with the energy of a brush or knife, but not permanently. This will seal the surface so that oil does not leech into it or cause it to rot.
Jackson's Thixotropic Alkyd Oil Primer Linseed Oil 1L For Canvas Paper Ground
Winsor & Newton Griffin Alkyd Oil Paint Titanium White 200ml
M. GRAHAM WALNUT ALKYD OIL MEDIUM 8FL OZ / 237 ML NEW
Gamblin Solvent-Free Fluid Alkyd Medium Safflower Oil 125ml For Oil Painting
Winsor & Newton Griffin Alkyd Fast Drying Oil Paint 37ml - Buy 5 get 1 free
Winsor Newton Griffin Alkyd Fast Drying Oil Paint 37ml - 48 Colours Available