Question re using black underglaze

[LaniSelick]

Hi,

I would like to make a piece with a black base/background and a multi-coloured design over top.

Is it possible to paint on top of black underglaze with other colours so that the overpainted colours stay true and pure instead of mixing with the black to form a mixed colour? 

Thanks, 

Lani

 

[Roberta12]

@LaniSelick I did this very thing as a test.  I wanted to see if the black underglaze would "swallow" the brighter colors.  My testers were made of  midfire porcelain.   It didn't.  But you would need to test test test to see if it would work with your underglaze and clay body and firing schedule.  

Roberta

[Callie Beller Diesel]

The ones I used didn’t tend to bleed into each other during the firing, but to go light over dark I had to make sure to put a thick enough layer on to be opaque. It was kind of tricky for any mark making kind of gestures, or anything where you’re only wanting to apply one layer.

I did not fire the black on before trying to add colours over top. Maybe this would prevent brush smudging/mixing? That was as far as I got with the technique. I kinda stalled on it and did something else instead.

[Bill Kielb]

On 5/17/2022 at 2:48 PM, LaniSelick said:

I would like to make a piece with a black base/background and a multi-coloured design over top.

Is it possible to paint on top of black underglaze with other colours so that the overpainted colours stay true and pure instead of mixing with the black to form a mixed colour? 

Definitely possible but firing (to bisque) and adding your next color is the safe route and can provide a more precise canvas. This can be done more than once for layers. See the bright white on black, and red and yellow accents. I believe we laid down the black on greenware, then bisqued and added bright colors over the top. Since I sprayed this glaze, we did not re-bisque. It just went into the glaze firing.