Stamping Porcelain

[kateC]

Hello all

I'm after some advice:

 

I'm slipcasting some porcelain baubles and want to stamp coloured names on the front of them (a bit like the words on these). So I bought some rubber letter stamps and some stain and borax frit, thinking I could mix stain with frit and a drop of water and use it like ink on the soft cheese stage greenware.

 

What I ended up with was a smeary blotch on my bauble, which was also dented out of shape by the pressure when I applied the stamp. Does anyone have any tips or advice on how I can achieve crisp, clean, coloured lettering?

 

Many thanks in advance!

Kate

[Chris Campbell]

First tip would be to wait a bit longer until the surface firms up more to avoid dents. I might even bisque them before applying the words but you don't have to. The advantage of putting the words on a bisqued piece is if you make an error you can just wash it off.

 

Second tip would be to try liquid underglaze colors instead ... They tend to stay where they are put.

Soak a sponge with stain and use it like a stamp pad ... Or if you have a dried up old stamp pad, load it with underglaze.

[kateC]

Thank you so much Chris- I was hoping you would reply.

I'll crack on with some more experimenting- it's quite disheartening when the great plan you formulated in your mind doesn't actually work in reality!

 

I'm using Parian slip (which matures at 1240). What temp do you think I should bisque to? Also- do you think the spheres are likely to slump in the kiln? This is my first time using a slip of a porcelain nature and I've heard lots of horror stories about it's temperamental nature (I usually use very forgiving earthenware).

[Chris Campbell]

I am assuming you mean 1240C right? I would bisque around Cone 06 to leave you with a fairly open clay body to absorb the underglaze cleanly.

I would have to see an image of your form to tell if slumping will be an issue.

As a rule of thumb with fine porcelain, once your shape gets flared out beyond the point of self supporting you need to support it. I have found 'almost round' shapes present no problem since they seem to be naturally self supporting.

However, I am not a slip casting person, so for all I know slip might be different ( but I don't think so ).

 

This post has been corrected.

[ayjay]

I am assuming you mean 1240C right? I would bisque around Cone 6 to leave you with a fairly open clay body to absorb the underglaze cleanly.

 

 

I know you all get confused over there with Centigrade,  

 

 but......................Cone 6:  Really? 

 

Did you mean 06 ..........@  approximately 1000°C?

[neilestrick]

Stamp the letters when the pot is on the soft side of leather hard. Bisque to 06-04, then fill the letters with underglaze, and wipe any excess off. This is how I do business logos on mugs.

[Chris Campbell]

 

I am assuming you mean 1240C right? I would bisque around Cone 6 to leave you with a fairly open clay body to absorb the underglaze cleanly.

 

I know you all get confused over there with Centigrade,  

 

 but......................Cone 6:  Really? 

 

Did you mean 06 ..........@  approximately 1000°C?

Oopsy! Yes, I certainly meant Cone 06 and will go there and edit the post now ... Thanks!