Originally Posted by hellosailor
Dunno about brands, but there are kevlar/aramid "ribbon" tire liners that you can put in between your tire and the tube. They're sold as a loop, sized to fit specific tire sizes, in the belief that if you can't puncture that outer ribbon--you can't puncture the tube on the other side of it.
Not expensive, not heavy, web shops like BikeNashbar carry them.
Yes, I've used these, and they work 90% of the time...the 10% they don't is when a chunk of glass bounces off a curb and into your sidewall.
I would never recommend going to a heavier tire unless you do BMX or "back-country" cycling. Gravel roads are still roads. I would go with a 1.5-1.6" lightly treaded economy tire like a Continental, and make sure it is at least 90 lbs. PSI...hard is fast. Put in the Kevlar liners to keep "cuts" from letting in grit, which is what kills the tubes.
I have a Marin Point Reyes with 110 lb. PSI 1.4" slicks, but I'm in a city. I do ride year round, however, even in snowy Toronto.