A STUDY OF FRENCH PAINTING CANVASES
Katrina VANDERLIP CARBONNEL
THIS IS A simplified explanation on the Gay and Monrocq identification technique used. Please refer to their article for greater detail and the name of the materials used:
- take a one-inch thread of the fabric to be identified.
- tie a thin cotton thread to the middle of the sample.
- dip the sample in a clear plastic mounting medium.
- thread the cotton through a fine clear flexible vinyl tubing 2 centimeters long and no more than 2 millimeters in diameter.
- draw the wet sample with the mounting medium up to the center of the tube.
- let set.
- place the tube vertically under a microscope so that the view is on the round opening—we used a special holder to insert the sample tube vertically under the microscope ready to cut cross sections. This is an instrument called a FIBROTOME designed by the Institut du Textile specifically for fiber cross sections. I imagine a substitute could be invented—the idea is to hold the tube containing the sample vertical so that the view down the microscope is on the opening of the sample tube. The thickness of the section can be controlled by screwing (and unscrewing) the base of the FIBROTOME, which raises and lowers the tube.
- cut the tube containing the sample with a clean fine razor to make thin discs.
- pick the sections up and dip them in red dye to tint the different parts of the fibers.
- sandwich the sections between a slide and a slide cover with a resin.
- identify the same. (It takes studying a good number of both hemp and linen cross sections before you can unhesitatingly label an unknown sample.)