Mishima is a similar way of decorating pottery to sgraffito, in that you are carving into the pottery surface.  However, with Mishima, you are coloring in the carved line rather than using the carved lines to expose the underlying clay.

Daderot, Public domain, via Wikimedia Commons

There are different ways to Mishima clay. 

Here 3 different Mishima techniques:

Mishima Method 1

Carve your design into your leather hard pottery.  Then paint underglaze or engobe over the area carved lines.  You don’t have to cover the whole of your piece, just paint the carved area. 

When the color is touch dry, take a damp sponge and carefully wipe away the color on the surface of the clay surrounding the carving. 

Be careful that the sponge is not too wet.  If it’s very wet you can wipe away the color in the incised lines too.  And you can also smear the clay ruining your carved design.

This will leave the underglaze or engobe in the carved lines and clean up the rest of the pot.

Mishima Method 2

Instead of wiping away the excess underglaze or engobe, you can scrape it away using a sharp edge.  This can be a metal rib or the flat wide edge of a modeling tool. 

This can be an effective way to remove the unwanted color.  And it also gets rid of any balls or burrs of clay left behind by the carving process.

Mishima Method 3

Another way to make Mishima pottery is to paint your pot with wax resist.  Then carve your design through the wax resist.  The colored underglaze or engobe is then painted onto the incised lines. 

The wax resist makes it very easy to wipe away any excess unwanted color on the surface around the carved lines.  And the wax will burn away in the kiln when the pot is bisque fired. 

Reference -  thepotterywheel.com -