This was created using Mentality polishes. The base uses Mentality "Dignity" which is a light grey-lilac with a matte finish. For me, this had a pretty awful formula. It was thick and streaky, no matter how you applied it, and I would definitely not be happy wearing it alone without stamping to cover up all the flaws and brushstrokes.
I have quite a few of Mentality's Matte polishes, and though they have some very pretty colours, I've found many of them have this same formula and are generally a disappointing purchase as they are so difficult to work with. That said, the polishes by Mentality in their Opaque range are wonderful and stamp amazingly well. Here I used their "Purple Opaque" to stamp over dignity, and despite all the issues I had with the base colour, I did end up quite liking how this turned out. The stamping plate used here is MoYou London's "Princess 12"