Print with a 10+mm brim with 0.1 brim separation gap to keep the print stable and if you want to be safe lower the print speed for the first couple of layers.

The “inside” is painted with: 

https://intent-to-supply.myshopify.com/collections/black/products/black-4-0

If you want the print to really stick to the model then either print with fuzzy skin or sand the part a bit before painting it.