Hi Toshi, I have used a couple of shades of timber mate, ebony & natural, and it sometimes comes out of the container in a gooey, sticky sort of way where you just add small amounts of water to help thin it down into a paste like slurry to then apply to the body with a spatula. One of those silicon kitchen ones used for cake decorating would be good to use. An old credit card is what I used and that did the trick too.

Suggest you dig some timber mate out into a plastic container (takeaway fried rice containers are a good size) add the black ink or dye to it first and mix that in as the ink or dye may be watery enough to create the slurry. If not, maybe just adding small amounts of water at a time between mixing until you get the right consistency.

It will smell like plastic whilst wet and still stinks next day once it has dried out.

WARNING: When sanding off the timber mate you need to wear a dust mask as you don't want to get any of the fine particles in your eyes, nose or mouth and either vacuum or sweep up the mess as soon as possible otherwise you will always have wind blown particles swirling all around. On mine I did all the sanding outside near a garden and just swept the mess into the garden bed as once wet it dissolves away.