Beginner Mulling

The medieval methods for grinding pigments correctly are described in many treatises.

12^th c De Arte Illuminandi (Thompson and Hamilton 9-10, 14-17, 18)

15^th c Il Libro Dell'arte (Broecke 56-93)

15^th c Bolognese MS (Merrifield 502)

and a slightly later discussion about muller composition in 17^th c Brussels MS (Merrifield 770)

Natural Pigments' tutorial on preparing a grinding surface and making gouache is helpful!

http://www.naturalpigments.com/art-supply-education/water-based-paint-pigments/

They say mulling is important for pigment dispersal in the binder and the paint's final appearance.

The steps I use...

Step 1: Gear up; you don't want to breath or touch even the non-toxic colors. Put a damp white cloth on your firm surface under the glass slab to increase contrast and add stability.

Step 2: Prepare glass: I used silicon carbide with just enough distilled water (DW) to form a paste the consistency of toothpaste. Used the muller to grind for 5-10 minutes to form a roughened circle on the glass slab as described on the website. Then I cleaned everything with soap and water.

Step 3: “Now that the grinding surface has been prepared, you can begin to dispersing [sic] pigments and making your own paint.” Grind the dry pigments with distilled water to avoid contamination. Put a walnut sized (Broecke 57) pile of pigment into the center of the slab. Add DW a drop at a time, mixing with a palette knife or other tool until you reach toothpaste consistency.

Step 4: “Holding the muller firmly with the heel of your hand down and your thumb up, slowly move the muller in a circular motion while keeping the pigment in the center of the surface. The pigment will slowly accumulate along the outside of the circle. Use the spatula to move the paste to the center of the grinding surface in order to continue grinding.

If the paste becomes too stiff, add more water a few drops at a time... remove any accumulated pigment from the sides of the muller using a spatula, putty or palette knife.

Sometimes suction will form between the muller and grinding surface... Use the spatula as a lever to raise an edge of the muller. Then slide the muller horizontally off the grinding surface.”

Clean all tools thoroughly between each color; observing your local toxic water disposal requirements.

Step 5: Combine mulled pigment with a binder. I use commercial gum Arabic from Winsor and Newton. Other binders include glair (egg white), egg yolk and other gums.

References:

Broecke, Lara. Cennino Cennini's Il libro dell'arte, A new English translation and commentary with Italian transcription. London: Archetype Publications Ltd., 2015.

Merrifield, Mary P. Original Treatises: Dating from the XIIth to XVIIIth Centuries on the Arts of Painting, in Oil, Miniature, Mosaic, and on Glass; of Gilding, Dyeing, and the Preparation of Colours and Artificial Gems; Preceded by a General Introduction; with Translations, Prefaces, and Notes, In Two Volumes. London: John Murray, Albemarle Street, 1849.
Medieval and Renaissance Treatises on the Arts of Painting, Original Texts with English Translations. Two Volumes bound as one. New York: Dover Publications, Inc, 1967.

O'Hanlon, George. Making Your Own Water-Based Paint. 2015.

Thompson, Daniel Varney and Hamilton, George Hurd. De Arte Illuminandi, the Technique of Manuscript Illumination. New Haven: Yale University Press, 1933.

Thompson, Daniel V. The Materials and Techniques of Medieval Painting. Dover Publications, Inc., New York, 1956.

Adrienne d'Evreus, 2016. http://scientistsscroll.blogspot.com