Ironically, given the economic and cultural advances in China over the last few years, good bristle may become still more scarce. The Chinese people are starting to keep the best bristle for themselves, and the bristle they're exporting they're rushing out of the country, not cleaning it as well as they once were. American brush manufacturers are then having to do that work, and that's increasing our costs. Adding tariffs, bristle has gone up 45 to 50 percent in just the last two years alone. When you're dealing with fine varnishes or enamel, bristle still has a leg up.
Some manufacturers go a bit further.
While most contractors are going to use synthetic filaments in latex, there are a certain number of contractors who are quality conscious and who choose to use bristle with latex. Yes, the life of the brush is shortened in latex, but it also allows the contractor to get by with one coat and in many cases finish the job smoother. For contractors looking for even lusher tools for smoother finishes, Rose's company offers a kind of upgrade on bristle brushes, a blend of bristle with European ox ear hair, a product it started marketing in the early 1950s when the Korean War prevented American companies from dealing with Chinese companies. It takes five or six ox ear hairs to displace the bulk of one bristle filament, which means that you have more filaments touching the surface, meaning fewer brush marks. If using natural bristle brushes with latex isn't for you, the good news is that manufacturers of synthetic filament brushes have been making great strides toward duplicating natural bristle's smooth finishing capabilities, while at the same time retaining the durability of synthetic filaments.