The thicker the drip line, the more durable it’s going to be to external damage or to system pressure. It will offer greater resistance to physical damages and will allow operating the system with a wider range of pressures. Thinner drip lines are better-suited for removal every few years or even every crop cycle. They’re also less expensive so replacing them isn’t a huge cost. Medium-walled drip lines sit somewhere in between, offering a balance between cost and longevity.