The filler masterbatch refers to adding various of additives, filler and little resin to form the masterbatch for the convenience of operation.
We always met the customer, once knows the main contents of masterbatch is CaCO3, would say: Oh this is made of stone powder, I am sure it cann't be used. We figured out why they react like this, maybe the CaCO3 masterbatch they tried before must be in lower price around 300usd, and maybe the effect is not good, for this kind of customer, they have reject the CaCO3  in their mind, we cann't help.
There is another occasion that the cheaper filler they use, the much cost they reduce. Maybe it works for the factory who doesn't require much to the quality, but it doesn't work for all the factory. We know that the adding ratio of filler masterbatch is 5%~30%, for example, for one product, adding 20% filler with the price 300usd, the cost is 60 usd, if they use the 445usd one by adding 30%, we can calculate the price difference by calculate 10% price of plastic and minus the price of filler. There is another occasion that we must choose better filler masterbatch, take 10% adding ratio for example, for the 300 usd is 30, 370usd is 37, for one ton the price difference is 7.5, but for the filler, the quality for the price 300 usd and 370 usd differs so much, only 7.5 usd difference, the quality will increase a lot, but there are few customers would like to consider it like this.