Eggplant Stromboli.

Playing with 2 inks, I bought in New York Central art supply store and Kuretake brush pens for color. I mixed 2 colors and it gave me rich sunny sepia tone, just don't know how it will behave in a jar, will dry out or remain fresh for the next drawing? I am trying to juggle 3 small murals, another probably unpaid project with chemical experiments, life, relationships, cooking vegetable pan fry noodles with coconut milk and keep sanity. Walls for murals sucking in, so each brushstroke weirdly stays in, like gouache, doesn't help much using both hands, to apply and blend right away with second hand.