Anodic painting of niobium/titanium

Howdy Folks, Is it necessary to use resistance when using a brush
or sponge to ‘paint’ the colors on niobium or titanium? If so, what
value or range of resistor values should be used? Any suggestions
appreciated. Carl 1 Lucky Texan

You could drop a resistor in (125-400 Ohms @25watts). Easier is to
lower the concentration of your bath to slow the process down. Cut
it in half with water and again if you see steam or burn marks. Bill