Walnut oil is naturally less yellow and dries slower than Linseed oil. Leonardo Da Vinci recommended Walnut oil, and from the Renaissance onward it was used for whites and light colors. Chelsea Classical Studio Walnut Oil Pale Cold-Pressed™ is extracted using the time-tested method of cold-pressing oils. This method follows historic precedent by using the most natural oil and extraction processes. Cold-pressed oils are obtained by pressing and grinding seeds in a stone or metal press. This historical extraction technique yields less oil than using heat or chemical methods, traditionally it was preferred in order to have a purer oil. Raw cold-pressed oils have a dark yellow-orange color that can affect paint color. To make the oil lighter in color, CCS Walnut Oil Pale Cold-Pressed is washed and cleaned using natural processes documented since the Renaissance, without harsh chemical cleaning and bleaching.