Saturday, August 27, 2011

Mixing Mason Stain Slips

Today I'm mixing mason stain slips. Here's one of my new jars filled with aqua slip. I'm so happy I found these wide mouth canning jars to use. I just mixed up a whole new batch of slip and filled each new jar with slip and different stain colors.

I thought these baby food jars would work well but the lid barely makes half a turn and doesn't seal. For over year now I've had a terrible time with the stained slips drying out that I've been using.

See how dry this slip has become in the baby food jar. I end up having to keep adding more water and remixing the slip stains every time I use them.

When I'm working on a piece I scoop a bit of slip out and put it into one of these glass condiment bowls. I dip my brush into these bowls so I don't contaminate the whole batch in the jar. But it's a pain in the neck to keep remixing the various colors of slip each time I use them because they've become so dried out.

So today I started out with some bone dry white clay. In this case I am using cone 6 Frost porcelain clay. I like a nice white clay to mix stains because the colors are less affected by a whiter clay.

I put the clay in a deep stainless steel bowl and add enough water to cover the clay. I use bottled or distilled water to mix my stains. I set the bowl aside to slake down.

Once the clay has slaked down completely I put the bowl in the kitchen sink with a towel to catch the splatters. I don't want any clay going down the sink drain. I mix up the slip with a hand held mixer on low speed.

Here are my new jars, nice and clean and ready to use. I'll be able to mix and store twice as much of each color slip now.

After I have the slip all mixed up I put a measured amount in each jar.

I then add a measured amount of mason stain into the jar of slip and mix it up well with a small rubber spatula. Using a flexible spatula enables me to smooth out any lumps that might form. This frost porcelain usually doesn't get any lumps as long as I mix it well and keep it well covered in an air tight container.

Here's my new batch of slips; I write the color of each slip on the top of the jar. The top photo shows what one color mixed up looks like. As I empty the baby food jars I'll phase them out. I may need to get four more small canning jars to mix up a few more colors. I keep one jar of plain slip on hand. I hope these new jars don't dry out. I'm getting bolder with some of my slip painting so stay tuned. Thanks for reading and for all your comments.


  1. I'm sure those new jars will help you with your work. Sometimes we put up with things that aren't quite right and it just dampens the creative spirit. Some nice looking colours there too. :^)

  2. Hi Anna, thanks, I think it did dampen me a bit, sometimes I'd put off making some new pieces because I had to mix up the colors I had to use and they'd get dried bits of clay, now maybe I'll be more productive.

  3. They look nice too, that always helps. Hope they work out.

  4. Hi Dennis, thanks my other jars were getting rusty lids and real cruddy looking. Ha.

  5. i keep slip in cleaned out yogurt or sour cream containers... very unattractive. When I am done using slip for the day I pour a little water over the top. The next day (or two weeks later) you can pour it off the top and your slip will be the right consistency. I use this method with my slip trail bottles as well. I only clean the tips at the end of the day, then pour some water in. I learned this trick from one the slip trail decorators at Salmon Falls Stoneware in Dover, NH.

  6. Hi Linda, Your work here is inspiring me to start working with stains more, instead of buying expensive commercial glazes. I'm really curious how the Frost Porcelain is going to work. I have a bucket of bone dry Frost trimmings. I use plain slip a lot and have a problem with algae growth after a week or two.
    BTW.. Where did you find your little mason jars?

  7. I had a comment here and blogger ate it more later.

  8. Hi Michele, thanks, the water on the top is a great tip, thanks so much I will try that.

    Hi Cindy, thaks, I got the jas at wally world and I just went back today and got another box of four, I suspect they will quit carrying them after canning season. today I had a eureka idea about once firing my recent pieces and putting a non glaze surface on them, what a cost savings that would be.

  9. should be thanks and jars, Ha, what a speller I am

  10. Just read this. Clayworks uses plastic containers that are round and have lids that pop off- not sure who they're made by. They work great-- and are at least three times bigger than the ones you have. if you're really interested, I can take a picture of one. anyway...

  11. I'm a new to pottery. Just started throwing about a year ago. I'm having a terrible time with glazes. Can you tell me how much of the Mason stains and how much slip you mix together? Looks beautiful!

  12. Hi Sandra, thanks, I just mix by eye and the colors are fairly try, if you don't want to use slip you can mix with water and frit, equal parts stain and frit and double water, I use stainless steel teaspoons and usually use a quarter teaspoon of stain and frit and half a teaspoon of water, keep mixing the stain as you use it because it settles out, in the slip it doesn't settle out but can make a slightly rough surface on the clay. When mixing into slip strain your slip and add a small amount of water to stain before adding to slip. Use a mask when using mason stains. Good luck.

  13. Hi Linda, I've just started using stained slip again. I've followed your advice and put them in 4oz and 8oz mason jars. Would you happen to have test tiles for you stains at cone 6? Which gloss glazes do you use over the slips?

    Your work and Barney are beautiful.

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  15. Hi Linda,

    I had disastrous with stained slips last year firing at cone ten. The only one that came out somewhat decent was Mango. This time I'm mixing with purchased porcelain slip and following your advice to use mason jars. The 8oz jars are perfect. Do you have any test tiles of the stained slips fired to cone 6? Which clear gloss do you use over the stains?

    Thanks Eve

    1. Hi Eva, thanks, I have been using amaco satin clear or amaco snow celadon. google image for wall tiles - Linda Starr wall tiles, you'll see some of the tiles I have made, the most recent ones I am using the mason stains mixed with water and frit, some of the tiles I once fired and didn't put a clear because they were going to be wall hangings and they didn't need to be food safe.


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