[Nathan]

The contract between you and the manufacturer needs to be viewed. Does it state they are allowed to send out a product that is out of spec?

My point of view (take it with a grain of salt):

Lab batches versus production is going to be different no matter what. Lab work is a more controlled environment. If there is a colorant in the bar, there should be a Pantone range that is preapproved on the spec sheet. This makes life easier in production. The only real-time this is a problem is when you have natural colorant. Sometimes, the color hue is different from supplier batches (this is what the contract manufacturer receives)

What is the fill weight specified on the product? Does it meet the claim weight that is on the packaging?

Sometimes, the product spec sheet will have a fill weight that is too narrow, and it is very hard for production to meet the requirements. It should be wide enough so production can meet the specifications.

If the bars do not meet the fill weight claim, production should rework the soap bars to meet the claim weight.