However, I could imagine someone that can't find an existing rosin that does what they want could be very happy with the ability to tailor the characteristics of their rosin like Leatherwood allows. Another option is to do it manually with your preferred brand of rosin. A colleague of mine plays with a blend of Melos Light/Dark, and determines how much of each she puts on based on how her bow/strings behave in a given temperature and humidity.
People who like soft, fluid, rosins (which is very popular among my high school students) will be pleasantly surprised by D'Addario's Kaplan Artcraft Light, which is very similar to another much more expensive premium rosin product, and a bargain at only $9: https://www.daddario.com/products/orchestral/rosin/kaplan-artcraft-rosin/
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