It is not always easy to get a firm grain with all types of raw hides, especially if you want to mill the leathers. The nature of the hide and the type of liming used can make the task difficult either because it can be too spongy or because it has areas with looseness to be blocked.
Natural defects such as veins and scars also decrease quality.
By employing systems and products with an effective filling effect, we can increase the choice of leathers by hiding some defects. Highly performing products make it easier to obtain a tight grain or with a very reduced looseness in the areas which are less firm in the beginning.