How to replicate compositions of discontinued paints?
I'm wondering if adding 1 ounce of Elmer's glue to 100% acrylic paint would duplicate the old formula?


No.

Paints are a specific mixture of a number of components designed to fulfill their role well in this specific combination. If you go and add a random additional ingredient, which in itself is not a pure substance but a nondisclosed mixture, you cannot predict what will happen. At best, the additional ingredient does no good and no harm. At worst, you can throw away the entire can of paint.

Paint companies also do not disclose key data about their mixtures for the obvious reason that they don’t want to be copied. So even though it may say X, Y and Z on the back of the can, that doesn’t mean you can infer much about the mixture. Even if they give percentages, you don’t know what all the rest is. Therefore, you cannot duplicate the old formula unless you have access to the full blow of analytical methods and a sample of the old paint.

Finally, I’m not even sure if changing vinyl acrylic on the packaging to just acrylic has any implication on the content of the can. It could just be a new choice of description.