For cleaning brushes, paint thinner is best since it's half the cost of mineral spirits and basically works the same. Other than the price, the differences between the two solvents are subtle: Both are petroleum products. Both can be used to thin oil-based paints and varnishes and to clean paintbrushes.
Thinners, paints and solvents manufacturing process can be made easily using, economic regular raw materials and chemicals, just you need to buy the formulas online from www.buyformulas.com for producing and manufacturing thinners. These formulas are recommended for new projects, small business and for beginners. 
