claybandit Posted March 29, 2018 Report Share Posted March 29, 2018 I've recently got back into ceramics after a fifteen year break to find out that a lot of my favourite products are no longer made. A good example of this is a fine black clay, made by Dorothy Fiebleman, sold in very small quantities for nerikomi work. I make ceramic jewellery amongst other things, and I used this black clay as a paint-on slip which I then partly scraped off to reveal crisp edges or underlying raised lines. I'm currently using velvets instead; Amaco Jet Black and Contem One Coat Black. The Amaco lifted and crumbled at the edges after bisque to 1,000, or it peeled back during firing, but I'm having better luck (so far!) with the Contem. Using velvets is not ideal for me as I require an opaque finish, so they need three coats. This is probably why they're lifting, and although I can reapply after bisque and prior to glaze firing, the quick hardness of velvets on leather-hard greenware, doesn't lend itself to scraping back. What I really want is my old Dorothy Fiebleman clay but oh well. Would anyone know of a jet black smooth clay alternative? Or can I colour my clay jet black but super smooth? It has to be extremely fine and the jettest of Jet black, not dark brown. Or if anyone has any old stock of Dorothy Fiebleman black clay? I can only dream. Link to comment Share on other sites More sharing options...
yappystudent Posted March 29, 2018 Report Share Posted March 29, 2018 Until I recently moved to another state I liked to use the "black" clay the local shop in Boise, Idaho sold ("The Potters Center" -it's the only store in the state, can't get it wrong) they just called it "Cassius". I'm not sure who the source was but it should be one of the big suppliers nationally. IF you fired it twice at cone 6 ((which I sort of had to trick them into doing, skipping the bisque fire)) it does indeed fire to a black-black with no trace of brown, with a very tight grain to it. However it does have a few flecks of some white grog, so few that in my test tiles they never even showed up, but sometimes in larger pieces they did, you might be able to pick those out, but my point is more about the firing. If you take the darkest clay you find available and medium fire it twice, the clay body might turn out quite dark. By doing this Cassius would end up similar to images I've seen of black porcelain, speaking of which, have you looked for any of that? Good luck, I like my dark clays too. Link to comment Share on other sites More sharing options...
claybandit Posted March 29, 2018 Author Report Share Posted March 29, 2018 Thank you Yappy. I'm doing lots of experiments at the moment, so I'll give your method a go. I have bought two types of 'black' clay, but both turned out brown. As for the porcelain, I would be painting it on to white earthenware and firing it to 1000 bisque and 1060 glaze, so I'm not sure it would fit. But you know what? I'm going to give it a go. It will certainly have the smoothness I'm looking for, and hopefully the colour, possibly not after 1000 bisque, but maybe after glaze, so that's two boxes out of three ticked. Good suggestion, thanks! Link to comment Share on other sites More sharing options...
Min Posted March 29, 2018 Report Share Posted March 29, 2018 I would make a porcelain slip coloured with black stain. There is a thread on that here, if your base clay is porcelain just use that for the slip base, dry it out and weigh it then add the stain, slake, mix and sieve well. Link to comment Share on other sites More sharing options...
claybandit Posted March 29, 2018 Author Report Share Posted March 29, 2018 Thank you Min. I've read the thread you suggested. Staining sounds like quite a long process, but as I only use a small amount of black anyway, it could be a solution as I can store it in small airtight containers. Link to comment Share on other sites More sharing options...
Chris Campbell Posted March 30, 2018 Report Share Posted March 30, 2018 Jet black Mason stain at about 5-6% ... good, solid black. It will take you about 15 minutes to mix it into any clay body and you will have it forever if you store it right. http://www.ccpottery.com/how_to_color_clay_with_maso.html Link to comment Share on other sites More sharing options...
Min Posted March 30, 2018 Report Share Posted March 30, 2018 1 hour ago, Chris Campbell said: Jet black Mason stain at about 5-6% ... good, solid black Did you mean Best Black Mason stain? 17 hours ago, claybandit said: Staining sounds like quite a long process Actually it doesn't take long to make stained slip, if you are using porcelain just let some scraps dry out, weigh them then add the weighed stain plus water to cover the clay and let it sit for a few hours. Mix it up and run it through a 80 mesh sieve and you are done with the making of it. It's easier to sieve slip if it's a bit on the watery side, just let the excess water evaporate after sieving. Your clay plus your firing temp will effect how black you get, try a small amount and if it isn't black enough add some more stain. If you are not using porcelain then you could either make a little porcelain slip from scratch yourself or try the clay you are using now for the base slip. Link to comment Share on other sites More sharing options...
Rae Reich Posted April 1, 2018 Report Share Posted April 1, 2018 I always wondered how Muhammad Ali would have felt about Aardvark naming their black clay "Cassius Clay". After all the (bleep) he took for changing his name, might it have been "Ali, formerly Cassius Clay" or simply "The Greatest"? I used it at ^06 for milk chocolate-looking jewelry when I discovered that about it. The obsidian black of ^6 didn't require 2 firings, though. Am I understanding you right, yappystudent? Link to comment Share on other sites More sharing options...
yappystudent Posted April 2, 2018 Report Share Posted April 2, 2018 12 hours ago, Rae Reich said: I always wondered how Muhammad Ali would have felt about Aardvark naming their black clay "Cassius Clay". After all the (bleep) he took for changing his name, might it have been "Ali, formerly Cassius Clay" or simply "The Greatest"? I used it at ^06 for milk chocolate-looking jewelry when I discovered that about it. The obsidian black of ^6 didn't require 2 firings, though. Am I understanding you right, yappystudent? When I first started about two years ago a shop fired my work with the Cassius. They did a greenware firing at cone 0-somesuch, I'm not sure the temp but a low fire. Then a glaze firing to cone 5-6. The cassius would turn first a sort of milk chocolate as you described in the low fire, then a sort of dull black with a trace of brown with some white grog in the ^6 fire; BUT if I then came back with the same (now fired twice, at low and mid range respectively) work, and said "fire this for me again at cone 6 please", and they would say "but didn't we just fire this you don't need to do that you don't know what you're doing" - then I would say, "yes but the black clay is much nicer with a second cone 6 firing and anyway I'm paying you is my money not green enough..." (in so many words,) they would fire it again at ^6 and it would turn a shiny, dense polished stone-like black with no trace of brown. Burnishing the greenware would make it look even better (couldn't find one of those beads for the photo), giving it a sort of hematite finish and looked beautiful without glaze. To be clear this shade and texture was not achieved with the low fire followed by a single mid-fire, it took at least two mid-firings. I don't recall if I tested skipping the low fire so I don't know if that was necessary? Edit: Nope you're right essentially, it's definitely darker that I remembered: So I dragged out some beads and photographed them; the Cassius is darker than I remembered at a single cone 6 firing; but there is a still a trace of brown, and at least to my eyes the texture is dull and uninteresting, -left side of the paintbrush. Not a great photo but you get the jist. Twice fired pieces on the left were not burnished, yet shiny, dense, lovely after a second cone 6 fire. Anyway, maybe I didn't give Cassius the respect he deserves at cone 6 once but I like him better 2x's. Link to comment Share on other sites More sharing options...
Rae Reich Posted April 2, 2018 Report Share Posted April 2, 2018 (Sigh of relief) We're both right. I can see the difference with the second ^6 firing - definitely more burnished looking, but without the labor, so, definitely worth it. Thanks for new info! Link to comment Share on other sites More sharing options...
claybandit Posted April 29, 2018 Author Report Share Posted April 29, 2018 On 3/30/2018 at 3:57 PM, Chris Campbell said: Jet black Mason stain at about 5-6% ... good, solid black. It will take you about 15 minutes to mix it into any clay body and you will have it forever if you store it right. http://www.ccpottery.com/how_to_color_clay_with_maso.html Oh my goodness thank you! I have just clicked on your link and I am in awe of not just your skills, but your generosity in sharing your techniques with everyone. You are really kind to do this and I've learnt a lot and have been inspired by your suggestions. Thank you so much! Link to comment Share on other sites More sharing options...
Chris Campbell Posted April 30, 2018 Report Share Posted April 30, 2018 You are so welcome! The teaching area of my website is a busy place .. it’s hard to find reliable information on colored clays. Link to comment Share on other sites More sharing options...
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