Q. Which is better - a nylon or canvas sheet and why. I want to use it for turnout, trailering, etc. Which would be more suitable, or would either be fine?

A. One isn't necessarily better than the other; it's more a matter of what you're using the sheet for. The canvas will most likely be warmer (unless the nylon sheet is lined with some warmer material), more breathable, and perhaps water repellent (some are, some aren't - check the labeling). It may also be stronger and less susceptible to tearing than nylon (unless the nylon is very strong and heavyweight). You might find a canvas sheet more suitable for daily stable use.