It is important to ensure that all of the mixes used on site are equal. All products are in pre-weighed bags of varying sizes to eliminate the on-site weighing of products. This can lead to having variations between the mixes and can give a stripy or patchy finish. One of the ways to avoid this is to mix up the bags off various pallets.
If one batch of stone is left in the mixer for longer than than another, the resin materials can start to absorb into the stone and create a colour change in the finish.