Source
r/Pottery•
kasbot

Underglaze help/suggestions- pear green

:snoo_shrug: Question! :snoo_shrug:

I was attempting to make a pear... and used a light green underglaze as shown here on a speckled buff clay, cone 6, clear glaze on top. It did not turn out as expected.

Does anyone have any suggestions for a more pear-like coloring? I'm thinking I'll just lighten the underglaze a lot more (and do some test tiles) or switch to a pear-y glaze (leaning to amaco potter's choice lustrous jade?)

This was handbuilt and I'm firing at a studio kiln.

https://preview.redd.it/h2ofj1p1o7x71.jpg?width=3024&format=pjpg&auto=webp&s=650e0b8b433fdf24d92877984df2396808853e31

Posted Nov 2, 2021, 5:20 PM UTC

516
a_smallbird•

I agree with some others suggesting you use a lighter clay since that will make lighter colors look brighter, but I just want to point out as well that that glaze does not look the same at cone 6 as it does at 05, which is what amaco normally shows on their test swatches for the velvet underglazes.

If you lighten it, it’s still going to look pretty earthy since the higher temp makes it look a little more brown, and they look darker when a clear coat is added.

Mayco Stroke and Coat might be an easy option (you can see how they look when fired to different temps online) Otherwise I would use something that is specifically sold as a mid range or cone 5-6 glaze, then the color you’re seeing is more true to the color you’ll get, or, use a low-fire clay and get that bright green you were expecting

9
kasbotOP•

thank you! this is really helpful information!!

1
OkapiEli•

I have found green underglazes come out much darker than expected. As you experiment, try mixing the green with white?

6
JLVins•

I think a lot of it comes down to the clay color and how many layers of underglaze you used. I might do a layer of white over the clay, then layer with green (maybe mixed with a little yellow and brown).

5
stilllearning70•

I think the clay colors really important a white would yield a much brighter green also it's important that you apply three coats of underglaze

1
tokhar•

You can also thin your clear glaze with water. I find using the standard density of clear glaze sometimes darkens and alters colors.

On the plus side, you’ve found your perfect combo for making avocados.

3
kasbotOP•

good to know! Thanks for that idea! I'll test that.

lol! I will have to expand my produce repertoire!

3
finding_feathers•

I've had luck with Amaco's PC-40, True Celadon over white stoneware!

3
kasbotOP•

thanks! I was debating between that and jade if I go the glaze route.

1
stilllearning70•

If you use a low fire '04 05 or 06 clay you'll find that the underglace will remain more true to the color that it looks like before it's fired

2
GoodDayClay•

Looks like you have a dark clay body. Try a white clay

2
OddTulip_nc•

you may want to put some white slip on when it’s still wet and apply the under glaze to bisque. or switch to white clay if you want vibrant colors

2
noticingceramics•

I'd be trying a white slip under that underglaze, because then you'd have a smoother, whiter surface for your underglaze. re: light green, speedball do one if you're looking for another green:
https://www.reddit.com/r/Ceramics/comments/loqrvy/speedball_underglaze_tests_fired_to_04/

but yes - you can totally mix underglaze colors to get what you want, but it can be tricky given color before/after firing, your clay body, firing temp and glaze over the top which can all affect the color.

also wondering if where you're getting these fired can help with suggestions.

1
kasbotOP•

thanks for the reply and info! I'll ask at the studio also (in between classes right now), but I appreciate all of the different ideas and approaches here. I have a lot to learn.

1
blunostagia•

I use amaco pistachio when I need a light green but I also use a lighter clay than yours.

1
Plantsandanger•

Usually when glazes better underglazes turn out darker or more gray/brown than expected because they got fired higher than the glaze should be fired to get a lighter color. Like, the glaze is certified to go to that higher temp that your piece did go to, but it produces a different result. Alternatively, I’m seeing what I think is some pitting, which is like little tiny pockmarks and bubbles in your glaze which would indicate to me that some thing happened to the glaze and it’s not actually what it says it is - usually pitting happens when something went wrong chemically, it’s usually more than just being too thick.

Clay body though is really important, the same underglaze is going to look different on porcelain vs B mix vs a different type of stoneware that might have grog in it or even iron flecks. And that’s just “white clays” - speckled buff isn’t really white, and clays like black mountain or Cassius or big red certainly will change what a glaze looks like!

1