There is not a simple correlation between the wet pulp and the finished product in the laminated paper industry, but if there is a change in color from one batch to the next there will be a color change in the finished product.
The task of the instrument in this application is not to compare the color of the pulp with the color of the laminated paper, but to see if a correction goes in the right direction. If there is a color difference after a small strip of paper is produced on the machine and laminated on a substrate, a correction has to be made. The pulp measurement helps to see if the correction goes in the right direction. For example, if a brown is produced, but the chroma should be a bit stronger, a yellow and red have to be added, but not necessarily the same amount of each. The pulp measurement shows immediately, if the correction goes in the right direction, and it gives you an idea of the extent of the correction even before the paper has been produced and laminated . This helps to save time and machine costs.
Another subject is the addition of waste. If a production is running, sometimes waste is added. The pulp measurement shows exactly how much waste can be added without changing the color significantly.
Last but not least, if a change in the process is made like adding new colorants, the pulp will be pumped from one chest to another one to mix it. The pulp measurement shows exactly how long it takes until the pulp becomes homogeneous.