Aldo Londi's Rimini Blue Glaze?

[Ben xyz]

Have always liked Aldo Londi's ceramic work from the sixties, particularly his Rimini Blue series done for Bitossi (Italy). Any ideas on the glaze(s) and firing temps? Thanks!

[Chilly]

Do you own this lovely creature? 

You can get an idea of firing temperature by touching your tongue to the bare clay on his feet,  If it is low-fired, it will suck all the moisture and try to stick itself to you.  If it is hi-fired it will not, and it will stay wet.

[Ben xyz]

I unfortunately do not own it, but appreciate the tip on finding out if something is low or high fired. Thanks Chilly. Londi's  work is quite collectible and especially known for this Rimini blue color. Perhaps still being produced by Bitossi. The pieces work well in midcentury homes.

[akilpots]

don't know what the glaze is but i think you could probably get pretty close in recreating it doing progression line blends with cobalt in a glossy base. looks like these pieces have a white slip on top of the body clay also. good thing is you dont need much cobalt to make a very blue glaze...bad thing is cobalt is pretty expensive these days.

[PeterH]

Example of cobalt concentration vs depth of colour
Cone 6 Ultramarine Cobalt Blue Glaze (Glossy Clear plus Cobalt Carbonate)
https://www.thestudiomanager.com/posts/cone-6-ultramarine-cobalt-blue-glaze-glossy-clear-plus-cobalt-carbonate

Tst
... but it doesn't have the cyan-ish tinge.

[Ben xyz]

Thanks Peter - the 1% cobalt is close. Agree with you that a little more green needs to be added to get a blue closer to cyan. A good starting place though. May throw the question over to Glazy. Perhaps an Italian potter knows the formulation. I have Londi's bio, which I haven't read yet - may provide a few clues. Will report back if I nail it.

[Hulk]

Looks like Cobalt Carbonate price has dropped recently!
Petalite price hasn't...

[Babs]

Think the blue is from Copper Carbonate, maybe a smidgeon of Cobalt,  just my opinion.

[Min]

11 hours ago, Babs said:

Think the blue is from Copper Carbonate, maybe a smidgeon of Cobalt,  just my opinion.

+1  

I think it's from copper carb in a high barium base glaze.

[Babs]

There was a glaze recipe, midfire giving similar finish, satin to gloss using petalite and copper carb, from memory.

If it comes to me, I'll post it.

Cone 07 to c03

Frit 3110 85%

Bentonite 2.5%

Petalite 12.5%

Copper Carb 5.8 seems high

Chrome oxide 0.2.

Note says crazes on most normal bodies. Glaze needs to be well set up with CaChloride to avoid settling.

Comes from Stan Eley's "Australian Fritted glazes" 1978

[Babs]

Lookibg further at the horse, yhe buckles of the bridle and the green medallions, could it be underglaze pver all the horse with a clear glaze? Would think the copper glaze wouls affect those colours , or those areas were painted and  covered before dipping in glaze.

[Kelly in AK]

It reminds me of a glaze known as “water blue” that uses copper carb. Some versions have strontium and lithium, some don’t. 

Edited August 25, 2023 by Kelly in AK
Added information.

[Ben xyz]

I'm guessing there may be Underglaze stripes of yellow w/ the transparent blue on top, making areas green. Thanks for all the input - good suggestions! Perhaps  the Bitossi people may share the formula (worth a try)...will contact. Didn't get much response from Glazy. 

[Babs]

Could always take a clear which contains either Lithium, petalite or Barium Carb and test tile them with varying abmounts of Copper Carb.  What cone are you firing to?

Ceramic Arts had a Wrights water blue of similar colour in its free midfire glaze download at one point. If you have a buff or dark clay body you can coat with a white slip to get the bright colour.

 

[Ben xyz]

Thanks Babs, Min and Kelly - all good ideas. Will also run this by my glaze chemistry teacher as well. Btw, contacted Bitossi, the manufacturer of the late Aldo Londi's work; worth a try, but no surprise:

"Thank you for your appreciation of our brand. I'm sorry, but formulas are absolutely company secrets! We are waiting for you to visit the Bitossi Archive Museum (www.fondazionevittorianobitossi.it) , which is open to the public on the occasion of the centenary of the manufacture."

Elisabetta Daini
Segreteria

[Marcia Selsor]

I think it is copper too. In an alkaline base

Marcia

[PeterH]

IIRC I've seen blue/green "copper" recipes with a little cobalt, and vice versa. Presumably it simplifies the final optimisation of the colour. 

PS loosely related

... which include a set of copper vs cobalt test tiles (for a specific base glaze)

 

Edited September 2, 2023 by PeterH