Making "bosses" (Little Bumps On Old Pots)

[Rebekah Krieger]

I have the stamp a friend made- does anyone have experience or tips to doing this? I was told to slip and score each one which is fine but I want to be sure its the most efficient way

[Min]

It's really hard to make out what I'm looking at in your photo... are you adding clay sprigs in the shape of 1/2 spheres?

[Mark C.]

I to could not make out what I'm looking at??

Mark

[Marcia Selsor]

are you talking about pate sur pate technique?

need a better description or picture. if tiny bumps, are they possibly dots of slip?

[oldlady]

bosses in brass or silver are fairly common decoration. if any of you are old enough to remember paper strips covered with colored candy dots they would be the sort of thing i think rebekah is looking for but whatever size she wants isn't clear.  the metal ones are made by pushing the thin metal from the inside and controlling the shape into a dot on the outside. pushing clay that way might be possible but it would leave an opening on the inside for dirt.  rolling a slab over a mat with holes in it would work, we have seen that often but throwing something is different.

 

 how you would do this with clay easily would probably involve a way to press a complete half sphere accurately and have it stick to the pot.  maybe make a strip of clay about 1/4 inch thick and whatever width would fit your pots, press a rounded pencil eraser into the clay to make a spherical impression and fire the strip to bisque temp.  that would make a bunch of dots once the holes are filled with soft clay.  then what? treat them like sprigs?  lots of work.

[Rebekah Krieger]

 

They are half circles pressed into a mold and then scored and slipped to be attached individually.  This is how it is done, but i was hoping maybe somebody had experience with this technique with tips. I think using slip is a smaller modern way of doing it.  

[Tyler Miller]

The Roman era Gallic and Germanic tribes (as well as Roman Egypt) used slip piped through a piping bag to produce an effect similar to what you're talking about.  The technique is called barbotine, which is confusing, because it's also the name in French for adding slip cast ornaments to a piece.  

 

Egyptian example:  http://en.wikipedia.org/wiki/Barbotine#mediaviewer/File:Roman_pottery_barbotine_cup.JPG

 

Example from East Gaul: http://en.wikipedia.org/wiki/Terra_sigillata#mediaviewer/File:Rheinzabern_samian_vase.JPG

[Rebekah Krieger]

thanks tyler. Those are cool. 

[Rebekah Krieger]

hopefully that works

 

It's the glazed piece. I don't like how the glaze is on sloppy. Does anybody have tips to apply the oxide wash on an uneven surface ?

[Tyler Miller]

Did you use something to suspend the oxide?

[neilestrick]

To get the same effect without adding all the weight of the dots and doing all that forming and scoring, hold a hollow tube on the outside and push the clay into it from the inside.

[bciskepottery]

Add some frit/gerstley borate/borax to your oxide wash and apply it during the greenware stage; the frit/etc is a melter that will help it adhere better and it is easier to clean up edges on greenware than bisque. After bisque, apply your clear glaze.

 

Also, when forming, add a shallow line below where you are putting the buttons; that will serve as a glaze stop and help control any running during the glaze firing vs. just applying the oxide wash. Also adds a nice focal point and accent to the form.

[Rebekah Krieger]

I can add some gersley borate. I did not apply until after bisque. I applied a clear coat over and that might be part of the bleeding problem.

[sandrad4553]

 I am a researcher.  I have a site that has many people come and ask information on their antique, vintage, or collectible items.  I do not do ceramics , but in doing research one must go to those who do.  I sincerely hope that I am not causing problems by doing this, but if it's a problem.... then please remove it.  I read your "bumps" title, and basically that is what I wish to know.  I have a vintage pitcher which appears to be clay on the outside and cased glass on the inside, but actually it is the raised, irregular surface dots that I am asking about.  I am quite familiar with Moriage where slip is used to make dots and designs... but this is not Moriage.  I am attaching two photos, and I would be so very thankful if someone could enlighten me as to what technique was used to make this piece, and better yet, who could have made it.  Thank you, S. Davis

[PSC]

That is a reticulated glaze on the outside and just regular glossy glaze inside. Here is a link to some info http://ceramicartsdaily.org/ceramic-glaze-recipes/glaze-chemistry-ceramic-glaze-recipes-2/lichens-and-lizards-and-leopards-oh-my-reticulated-glaze-recipes-for-wild-ceramic-surfaces/i don't know who made your vessel tho.

[Darcy Kane]

I have a friend who uses little dots on lots of her work.  She uses slip in a heavy duty zip lock bag and snips a tiny bit off one corner, then just pipes out her dots.  She does get little points on top of her balls so after they have set up a bit, she takes a damp sponge and gently goes over the tops and smooths them out.

[High Bridge Pottery]

Interesting pot. Never seen anything like that.

[oldlady]

check out "PotteryBoys"  website for the work done by glenn woods and keith herbrand.  g o r g e o u s!!!!  the matte crystalling pieces are so silky, velvety and have the bumps.