China Painting Flux

[Hyn Patty]

For those of you who do overglazing using china paints (or enamels for that matter - I use both as well as underglazing) flux is available to add to pigments to make them shinier or to use as a final top coat. 

There are various materials like zinc oxide that can be added as a matting agent to dim the gloss of overglazes.  This is normally added directly to the pigments to make them satin or velvety matte in the final finish.  Using too much though will lighten the colors, making black for example turn into a dark grey.

 BUT there doesn't seem to be an option for making a final top coat for a satin or matte finish to make all of the overglaze uniform.  I've tried adding matting agents to clear gloss flux and my tests still come out high gloss.  I have no option obviously of reducing the silica content of the flux, only adding tons more of the matting agents.  I will try more testing and much higher ratios to see if I can possibly make a dent in the flux high gloss but I'm worried it will fog. 

If anyone here has any suggestions, I'd love to hear it!  I've searched and searched and made lots of phone calls to no avail from china painting dealers.   I have one lead I am chasing but more leads would be good.

[Rae Reich]

Cone 018?

[Callie Beller Diesel]

So, my city does have a group of china painters, but they don’t have a lot of web based presence other than this link here.  This group has helped me with lustre questions in the past, but it’s been a while. They are a wealth of knowledge though.

[Hyn Patty]

17 hours ago, Rae Reich said:

Cone 018?

There abouts, yes.  Cone 016 to 018 range would be fine. 

This is NOT something that traditional china painting groups know about or use.  Trust me, I've been pursuing this for a  while.  I've chatted with countless suppliers and top workshop teachers.   Everyone either wants high gloss or at most uses matting agents to achieve satin finishes by adding it directly to the pigments.  That's the standard.  There is only one company I have found that still bothers with matte china paints at all.  It's long since fallen out of fashion, to be honest.  I did just pick up a /matte/ additive I am testing (rather than satin) but it also had no effect when added to a clear gloss flux.

So what I am looking for here is something very unusual among over glaziers but isn't absolutely /unheard/ of.  So I'll check the group linked to but yeah that's not likely a helpful source.  I am the queen of doing things outside of the norm or that people insist simply can't be done - and then making breakthroughs and finding ways to make it happen anyway!  It's kind of my credo.    If it's impossible, I accept the challenge and make it happen.

The other thing I'm looking for are NON TOXIC over glazes that are OPAQUE.  The enamels I have and use currently for that purpose are full of lead and cadmium and I just HATE to put that stuff through an airbrush - no matter what health precautions I take.  They are however compatible with china paints and fired in the same ranges more or less.   It allows me an option to go back and lighten pieces in select areas that just get too dark.  I do have a few leads there that I'm looking into but I haven't nailed anything down yet in the firing range I require.

[Callie Beller Diesel]

On the off chance he’s still checking in from time to time, I’ll tag @liambesaw. He was making lustres at one point, and might have some insight. 

[Rae Reich]

There are a few possibilities in James Chappell’ Clay and Glazes 1991. I have had success with his ^06 formulas, such as a wonderful eggshell matte for egg forms which plays well with Mason stains and oxides, but have not tried the ^018s.

https://a.co/d/6ZokMfm

EG-4 CLEAR SATIN MAT GLAZE ^018
alkaline, transparent, satin mat

Pemco frit #25   48.6  

Pemco frit #54   27.3  

Lithium carbonate   9.9  

Kaolin (any)   6.1  

Silica   14.1

(Add: CMC  1tsp.)

EG-6 CLEAR SEMI-MAT GLAZE Cone 016

alkaline frit,  transparent, semi-mat (avoid iron, tends to muddy)

Hommel frit #259.  54.4

Hommel frit #14.    38.8

Lithium carbonate.  8.0

Kaolin.   2.0

Add: Bentonite   2.0, CMC.  1tsp

 

EG-7 CLEAR SATIN MAT GLAZE Cone 016

Pemco frit #25.  42.6

Pemco frit #54.  27.3

Lithium carbonate.  9.8

Kaolin.  6.2

Silica.  14.1

Add: CMC 1tsp

There’s an alkaline frit, opaque, semi-gloss ^015 with chrome ox added for color you might test or modify

EG-13 SAGE GREEN GLAZE Cone 015

Hommel frit #14.  45.3

Hommel frit #259.  54.7

Add: 

Bentonite.  2.0

Green chrome oxide.  3.0

Titanium oxide.  8.0

CMC 1tsp (this glaze fires to a sage green at cone 015, if overfired it turns metallic)

 

[Min]

Any chance you could just do a delicate sandblast to take the edge off the gloss? Or a mild acid etch?

[Kelly in AK]

I can only turn this over in my mind, I have little experience with underglazes, a fair amount with very low fire (016-012). I used to do a lot of terra sigillata and burnished work. I feel like I understand what you’re after, you explained it well. A matte surface that retains the kind of saturated color a glaze has. (Your work is beautiful by the way)

So my thoughts are on silica and alumina. Silica is a glass former, yes, but also very refractory. There is a point in glazes where too much begins to matt the surface because it can’t melt in. It’s also clear, kinda, at least less than opaque. I wonder if actually increasing the silica would be something to play with. The other idea being about alumina, and increasing that (and silica) by adding a small amount of terra sigillata made from a light burning clay (OM4 was my first thought, it makes a very nice sig, but perhaps a kaolin). 

In my head the problem is to get everything to barely begin fusing, enough bring the colors out of that pale chalky phase, without going into full melt. The fine particles of terra sig begin fusing before their parent clays do. Just some musings.