I use many of their products. I have used moldstar 30 quit a bit, easy to use but a bit softer then I like, and it’s pricey. In all the lines the higher the number ie. moldstar 30 the “harder” they are, they list them in durameter. It depends on what you want to cast, as silicone interacts with the tin cure silicone and won’t cure. Platinum cure doesn’t react to anything. I recommend to anyone using smooth on to contact Reynolds advanced materials, they deal and use smooth on and are super knowledgeable. Plus if they are close they have stuff made you can touch and play with.
Ryan