Pirastro's Tonica viola strings are made with the very same kind of technology that the Thomastik Dominants are made. They have a similar synthetic core and also come in 3 gauges. Medium being the predominant gauge ordered. A lot of people that use the Dominants will usually like the Tonicas. Some players say that the Dominants are a tad brighter in tone, with the Tonicas sounding a bit warmer. Of course it depends on other variables, primarily the particular viola and the subjective requirements of the player as well. Tonica also has an additional C string that comes in Tungsten. If you have a slow responding C string on your viola, the Tungsten C might offer more 'zip' to it as it is a brighter and thinner string.