I have a vague recollection from back about 1959/1960 when as an apprentice boat-builder doing some of this canvas/paint stuff. One thing I remember is the boat-yard saving all the part used tins of paint, this was mixed together, old thick paint was considered "best" and this used in the job a really remember, it was trowelled onto the deck and then the canvas was laid on top, pulled taut and then we had to "squeegee" it into the paint, removing excess paint, nightmare job. Finishing was applied after this had dried.
Only did this early in the apprenticeship as it was superseded by a new system, this was a white nylon fabric used with a white resin. This was much longer lasting and was even used on hull exterior of quite large plywood boats. Danged if I can remember what it was called, good stuff tho.
Course, then there was 'Trakmark' ™