ARCHIVAL ODOURLESS FAT MEDIUM - Some painters like the matte effect of diluting paint with turps only. This can be done with Archival Oils, but drying to the sticky stage is quite rapid. Slow Drying is designed to give 24 hours working time. - 100ml - All these specialised Mediums are based on Alkyd Resins rather than Stand Oil or Linseed Oil so as to improve the drying characteristics and reduces the tendency to yellow. All these Mediums will maintain a similar degree of flexibility throughout the layers of a painting.