The success of the blacking process is based on the optimum running of your solution strength. To maintain maximum efficiency, it is important to regularly test the working solution strength of the solutions in the blacking line. The system has been developed whereby you will seldom find it necessary to dispose of a working solution, as the process is used the Working Solution strength becomes depleted, strength and balance of the solution is re-established by the addition – topping up – of Supplied Concentrated Solution.