Sgrafitto

A demonstration of sgrafitto, carving through a contrasting colored slip.

[@maurad5378]

Your work is beautiful, educational and inspiring!

[@Absolutebeach]

Lovely! Great teacher!

[@richardmccoll9297]

Thank you so much!

[@melissagraham4569]

Inspiring as always. Thank you,

[@richardmccoll9297]

Thank you!

[@lindatortorice9356]

Is it grams for the measurement in the slip recipe?

[@richardmccoll9297]

Yes, it can be weighed as grams. The recipe is by weight so you could also use ounces. Grams are easier to weigh from a percentage recipe and the total is easy to adjust for a small or large batch.

[@rachelmichie1824]

Thank you! I was wondering if you make your slips? I have been thinking of making my own slips but I have heard about several methods.... I’m not sure which one I should try.

[@richardmccoll9297]

Hi Rachel, 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

[@rachelmichie1824]

@@richardmccoll9297 Thank you so much Richard for this information; I really appreciate it. I will print it and try out some of your suggestions. Right now I am using a porcelain slip on a speckled stoneware clay (Cone 6), it seems to be working. I have heard that sometimes Potters will add an ingredient to a diluted slip so that it will fit several clay bodies...I’m not sure what that ingredient is(?). I have also wanted to add some cobalt carbonate or Iron Oxide. I would also like to make more ‘natural slips’ with less toxic ingredients ( I guess cobalts would not be great...). Thank you again. I really look forward to your informative videos.

[@richardmccoll9297]

@@rachelmichie1824 Hi Rachael, Thinning the slip will work because of the shrinkage of the slip will be reduced. If you apply the slip thicker you can run into problems. On the universal recipe that I gave you above I added a boron frit, Ferro 3134, which lowers the melting temperature, bonding and hardening the slip a bit which could work for you with your slip. A little is all you need. The oxides that are used in ceramics are safe to use in the oxide and carbonate forms. Avoid any soluble oxides such as cobalt sulphate because of the way that skin can absorb them. Manganese dioxide is usually only used as a modifier, for example to soften the intensity of cobalt, and to change the raw color to see better as you are working with it. Manganese is volatile in the kiln so it needs to be fired in a well ventilated room. There are many sources of chrome which are bad for you but chrome oxide is insoluble and can be used safely. Remember to always wear a mask when mixing dry ingredients with an N95 rating.

[@JW-yi7lv]

@@richardmccoll9297 I have just discovered your videos, they are great! Your response here is outstanding and I feel much more confident making and colouring slip. Thank you

[@hojoinhisarcher]

12 mon sep 22