A woodworker friend asked me what type colorants, pigment or dye, were used in Minwax stains. He had called Minwax and was told that they use only pigment, but this didn’t match with my friend’s experience. I found it not surprising at all that the Minwax tech didn’t understand his company’s products.
It’s easy to tell the colorant used in a stain. Let the stain sit on a shelf for a couple of weeks so any pigment in it has time to settle to the bottom. Then stick a light colored stirring stick about halfway down in the can. If the stain colors the stick, it contains dye because dye is dissolved in the solvent; it doesn’t settle.
Then put the stirring stick all the way down to the bottom of the can and see if you can pull up some solid colorant. If you can, the stain contains pigment because pigment isn’t dissolved; it is suspended in the liquid, so it settles.
You can use different stirring sticks for each test or just one. You can do this test with all brands of stain.
My experience with Minwax stains is that cherry contains only pigment. Golden oak and puritan pine contain only dye. All the rest I’ve tested contain both pigment and dye.
I have no idea why it’s this way. These stains were formulated many decades ago. I can’t imagine that anyone at Minwax today, after the number of times the company has been sold, knows why. But does it matter?
Not really. The key that makes these stains work differently from pure dye stains that are dissolved in just a solvent is that stains in cans contain a binder. In the case of these Minwax stains the binder is oil. In the case with General Finish’s “dye” stains, the binder is acrylic resin. It’s the binder that makes these stains work differently from what we call dye stains.
The only characteristic you need to be aware of, and maybe take into account, with the Minwax stains is that dye fades fairly rapidly in sunlight. Pigment is much more resistant to fading. So the dye in most of Minwax’s stains could fade if the stained object is placed in sunlight, even indoors through glass.
– Bob Flexner