As early as the 10th century, Venetian painters were using fabric supports for their church banners. Traditionally, icons were painted on wood panel and often ceremoniously carried in procession from one church to another on the feast of St. Mark, for example. But parading around waterways and through narrow streets carrying tall poles supporting wood panels must have been too great a penance. Venetians painters had to find another way. After replacing the paintings on wood panel with paintings on canvas, their banners could be carried longer and lifted higher without breaking any backs.
"Canvas" is derived from the Arabic word for cloth. Hemp, the oldest and cheapest fiber for cloth, might have been first choice for the early experimenters despite its coarse fiber and the open weave of most hemp (burlap) fabric. While more durable, hemp fibers absorb more water than linen. Hemp fibers are not suitable for dyeing. That fact - hemp fibers are not suitable for dyeing - determined hemp’s place in industry and agriculture.
Human beings want to be around color. We have been making paints to illustrate limestone walls, tattoo skin and dye fabrics for at least 100,000 years. Since time before the Egyptians, humans have cultivated flax and cotton, crops that produce fibers suitable for dyeing.
Fibers from both hemp and flax plants are harvested from stems. Flax yields both linen fibers and linseed oil and is among the earliest cultivated crops about 10,000 BCE. Linen threads are long tough fibers. Cotton, a short, softer fiber harvested from the plants’ flowers, was cultivated in the Indus Valley about 7000 BCE. Linen, cotton and hemp fibers, threads and cloth have been consistently traded by every civilization through history.
From 5th to 18th centuries, Venice was the trading hub bridging Europe, Africa and Asia. The crusades launched form Venice. It is well documented that in the maritime industry linen sail cloth with tight weave and pale color was widely used, especially for smaller sails. For artists, I doubt there was much discussion about the choice between hemp and linen as a support for paintings. Linen’s strength and pale color would trump price. In procession, colorful linen banners must have flowed like sails lifting the prayers and songs of the faithful into the wind.
Regardless of fiber, the most common weaving technique to make fabric is warp/weft: