GONZALES, TX - Effective Aug. 1, 2008, or as contracts allow, Southern Clay Products Inc. (SCP) will increase the price of its waterborne rheological additives, castors and wax derivatives by 5 to 15 percent. The increase includes Optiflo®, Bentolite®, Rheocin® and Advitrol® additives. These increases apply to all regions and are being implemented to help offset continuing increases in raw material and operating costs.