Students in my school have art once a week for a double (80 min) period
once a week, beginning in third grade. We all love it. It seems a little
long to me at the beginning (first two weeks of school), but I always do
long term projects anyway, so they very quickly adapt. It makes so much
more sense to only clean up once a week with them. It allows us to get a
lot more done to skip the extra setup/cleanup. Their classroom teachers
love it too, as it gives them a nice free double block to accomplish a
lot.