Neal, When I made Ketchup years ago, the recipe I used taught me the "Pillow Case" method of reducing the sauce. Although I don't make it any more as I don't use enough to make it worth the effort, I continue to use the "Pillow Case" method to make tomato sauce. You just take your tomato juice and put it into a clean pillow case and let the water drain out, the thick pulp stays in the pillow case. The longer you let it drain, the thicker the sauce gets. No scorching, stirring, or standing around waiting. I have a pillow case just for this purpose. I tie it up above the sink and let it drip. I remember the first time I tried it I was afraid I'd loose all my juice, but it works so slick I wouldn't ever again waste time letting it cook down. It seems to me to have more of a fresh tomato taste too.
I know I sound like a broken record telling about this, as I've done it a quite a few times, but it's such a slick deal I can't help myself