Slip trailing is another way of decorating pottery using clay slip.  One of the effects you can achieve when slip trailing is to add some texture to your pottery.

Slip Trailed Posset Pot, Maker Unknown. Image Courtesy of The V&A Museum

The only equipment you need when slip trailing is some reasonably thick clay slip and a slip applicator.  A slip applicator is sometimes called a ‘slip bulb’ or a ‘slip trailer bulb’.  The applicator has a bulb-shaped rubber container to which is attached a nozzle. When you remove the nozzle from the bulb, you can fill the bulb with clay slip. 

The easiest way to do this is to squeeze the bulb so that it is flattened. Then dip the hole into a container of slip and release the bulb.  Clay slip is then drawn up into the bulb.  Wipe the neck of the bulb down and then put the nozzle back on. Once the bulb is full of slip, you are ready to start decorating your pottery. 

Using a Slip Trailing Bulb

If you gently squeeze the bulb, a small amount of slip will come out of the end of the nozzle.  You can use this to ‘trail’ slip onto your pottery. 

This adds can add a lovely feel to the pottery.  And it can be visually quite stunning too.  The slip that you use can be a different color to the clay body.  Or you can use the same colored slip and simply use the trailing to add texture.

Experimenting with Slip Trailing

There are lots of different ways that you can experiment with slip trailing and other decorating techniques.  Here are a couple of examples…

• When the slip trailed texture is leather hard, paint the clay with underglaze.  Then when the underglaze has dried gently scrape away the very top surface of the slip trailed texture.  You can do this with a metal rib.

• This will remove the underglaze from the slip trailed design and expose the clay underneath.  The underglaze will remain in the recesses of the design.   
  
  
• Once the pottery has been bisque fired, you can use the lines and texture of the slip trail as a template for your glazes.  Textured shapes can be painted with different colored glazes, using the trailed lines as the outline of the design.

The nozzles for your slip trailer come in different gauges.  So, you can adjust the amount of clay that is trailed onto the clay, and control the type of texture you create.  

Reference -  thepotterywheel.com -