Designing glaze blends for colors

[2Relaxed]

I have finally found a base formula that doesn't craze on my very capricious porcelaneous stone body. Mixed a 2000g batch without any additives. I want to create a few blends to see what colors I can get but I'm a bit lost here now. I've only done one triaxial blend before (with a different base formula), and with this one I want to try so many things.   I'm looking for greys/blues/greens. Maybe a yellow or something close to it.  Don't want anything in the brown/caramel range.   I'm pretty sure they all will have to have about 5-6% of rutile based on the same base recipe I saw with colorants added. So, that leaves me with selecting oxides/carbonates. I'm thinking copper, cobalt and nickel, also RIO. I suppose if I want to add pinks/purples I'd have to use tin and chrome as well. There're so many variables though. How to systematize the approach to getting the colors I want? Is it better to do line blends? Biaxials? Triaxials?

[Bill Kielb]

3 hours ago, 2Relaxed said:

How to systematize the approach to getting the colors I want? Is it better to do line blends? Biaxials? Triaxials?

Line blends for colorant work for most, progressing from light to dark so one test can generate many shades from one small sample. Hey don’t forget mason stains.

[Callie Beller Diesel]

Biaxial and triaxial blends are great for fine tuning colours, for sure. If you do an initial biaxial blend to figure out intensity of individual colourants, you can then start mixing them together to fine tune the shades you want.

Use a light hand with the nickel, and keep it out of firings with mason stains you don’t want to shift the colour of. There’s a fine line between muted and muddy with that stuff. The only reason I don’t say leave it out entirely is because you want grey.

Blues and greens are pretty easy to achieve. If you want pinks and purples, you can play around with chrome tin pinks, but I’ve had great success with mason stains. If you want a sunshine yellow, you definitely want a mason stain.

[neilestrick]

I like a big triaxial blend when doing color tests. You get line blends along the sides and tri blends through the middle. The bigger the better if you want to get close on the first try. Hyperglaze has a section in the software called Potter's Friend that allows you to put in the percentages of the colorant for each corner of the tri, then it gives you a list of what goes into each tile. It has a nice 66 tile blend that gives you a ton of color variations. If you don't have access to Hyperglaze or some other program that simplifies the process, I'd be happy to plug in your stuff and post the charts here for you. I just need to know the percentage of each ingredient you want at the corner. Attached is a sample of a 66 tile blend with (1) 0.5% cobalt carbonate, (2) 3% copper carbonate, and (3) 4% rutile at the corners.

66 Tile Triaxial.pdf

[2Relaxed]

Thank you all for replying, and Neil, thank you for the generous offer of Hyperglaze help.  Callie, I like your idea of doing initial biaxials and then mixing them together, I hadn't thought of this approach.

I haven't tried Mason stains before and don't really plan to at this point. I understand that the results may be more predictable than when using oxides but I'm feeling adventurous right now. 

So, when planning to use oxides in blends, which combos, do you think, I should try? 

 

[2Relaxed]

Ooooh, I think this article will help me a lot: https://ceramicartsnetwork.org/pottery-making-illustrated/ceramic-glaze-recipes/glaze-chemistry/an-introduction-to-color/#

[neilestrick]

14 minutes ago, 2Relaxed said:

So, when planning to use oxides in blends, which combos, do you think, I should try? 

Copper carb, cobalt carb, rutile will give you a good set of blue-greens. Use red iron oxide to knock down the brightness of most blends, especially with blues. I think warm colors are easier to get with mason stains.

[2Relaxed]

Great, thanks Neil!

[Min]

If you are thinking there will be 5-6% rutile in all the glazes (expect chrome / tin red)  then I would add that to the base glaze for all points with your blends. That way you won't have to use one axial of the bi, tri or quad axial  for the rutile, it will give you the full amount of rutile in each glaze test. So for the blue / green trial I would do a triaxial and use copper carb, cobalt carb and red iron oxide for the 3 points.

If you don't already have one I would get a syringe with cc's marked on it to measure out the amounts. 

If the base glaze you are testing is either of the recipes I sent you a couple weeks ago I wouldn't bother testing it with chrome/tin. There isn't enough calcium in them to support this type of red. (plus the alumina is probably too high)

[2Relaxed]

On 9/18/2021 at 4:03 PM, Min said:

If you are thinking there will be 5-6% rutile in all the glazes (expect chrome / tin red)  then I would add that to the base glaze for all points with your blends. That way you won't have to use one axial of the bi, tri or quad axial  for the rutile, it will give you the full amount of rutile in each glaze test. So for the blue / green trial I would do a triaxial and use copper carb, cobalt carb and red iron oxide for the 3 points.

If you don't already have one I would get a syringe with cc's marked on it to measure out the amounts. 

If the base glaze you are testing is either of the recipes I sent you a couple weeks ago I wouldn't bother testing it with chrome/tin. There isn't enough calcium in them to support this type of red. (plus the alumina is probably too high)

Thank you Madeleine! I will take all these points into consideration.