Art Spectrum Oil Painting Medium #3 is used as the fattest medium in the sequence of painting by the"fat over lean" rule. It contains more oil and slower drying than Medium #2. Ideal for painters who prefer a heavier and more viscous medium.
Medium #2 can be fattened by gradually adding Medium #3 in 10% increments.

Art Spectrum Oil Medium range is also available in #1 and #4 Liquol