Applying Decorating Slip to Bowls

How to apply decorating slip to leather hard greenware.

[@madmonkeystudio-ajourneyin3220]

Can you please give some advice or a slip recipe and your colorants that you use in slip? What percentage? And anything special about your brushes? They look wonderful! Thanks 😊

[@richardmccoll9297]

Hi, My brushes are standard sumi brushes which I like because they hold a lot of material and can, depending on the pressure you use, created fine to thick lines. Slips should be designed for your clay body and temperature that you are firing to. The simplest slip is one made from the clay body that you are using (best if it is white or off white or your pallet of colors will be limited). Dry some of your clay (I use trimmings), the smaller the pieces the better. Break it up and crush the dry clay into small pieces and weigh out some and add your metallic oxides like iron, cobalt and chrome for color. Slips require more colorant than glazes so you can add up to 10%. Mix and add to clean water and allow the clay to slake. Dry clay breaks down to a nice smooth slip in a few minutes (faster the finer the particle size). When the clay has settled and made a smooth slip, pour off the excess water off of the top and stir. Adjust the slip to the thickness that you want by adding a little water at a time and stirring. If there are lumps, run it through a tea strainer then use it in good health. Robin Hopper, a Canadian potter, developed a slip recipe that he called a Universal slip because it would work on any clay at any temperature. I have adjusted and changed it to a new improved slip which I have used on pots fired from cone 06 to 11 successfully. This is the decorating slip that I use now. Try experimenting with different colorants and stains and let me know how it works for you. New Universal Slip: Cone 06-10 (Current GCC Decorating Slips) OM-4 Ball Clay 750.0 EPK/Kaolin 100.0 Custer Feldspar 25.0 Frit 3134 25.0 Silica 100.0 1000.0 1. For Dark Iron add: Red Iron Oxide 160 2. For Dark Blue add: Cobalt Carbonate 50 Manganese Dioxide 20 3. For Green add: Chrome Oxide 40 Cobalt Carbonate 10 4. For White add: Zircopax 200 5. For Black add: Mason 6600 Stain 150

[@madmonkeystudio-ajourneyin3220]

@@richardmccoll9297 wow! Thank you! I’m at school right now so going to make your slip with colorants and see how it works. Stay tuned! I really liked your oxide wash on matte glaze video too. I’m not a thrower so many of your videos don’t apply but looking thru to find your decorating ones! Very good! Thanks!

[@FFSS60]

Any advice to prepare locally harvested clay (soil) to use as a decorative slip? (i.e. additives to create more consistent application)

[@richardmccoll9297]

I would screen and test. Try the slip on your clay and fire, evaluate and fire again. It depends on temperature, atmosphere and your clay body. Screen through an 80 mesh screen and try it. There are some natural clays like Albany Slip and Alberta slip will make a good temmoku like glaze at cone ten. Some which may have a high alumina content may need some additional flux. It should be a fun exploration for you and can result in a unique, signature look. Good luck and have fun.