Wolstenholme International Inc. is committed to being a long-term supplier of high quality carbon black dispersions and providing high levels of service and support for its customers.  However, in order to do that, company officials say they can’t ignore the impact that recent economic conditions are having on its business.          As a result, Wolstenholme is planning to implement a 4 percent increase on all carbon black dispersion products, effective Jan. 1.  In addition, this October, Wols...