Probably one of the oldest methods to make a mark onto the clay surface and has been used throughout all ages and cultures. Anything can be used to make an impression from found objects of organic or man-made materials, coarse open-weaved 'textured' fabrics to complex hand-made carved stamps!
I'm opting for somewhere inbetween, by carving my letter into a plaster tile and making a stamp in clay, *Bisque firing it, to then, press into the 'soft to leatherhard' clay.
To make a plaster tile; a small mix of plaster is poured into an ice cream container, once set hard it's poped it out making for a nice neat smooth edged tile to carve into.
To make the carving easier I'm using my Dremel with it's U-beaut pointy tool, just right for the fine lines. I used to do all my carving painstakingly by hand with a carving blade, e'ons later....! Finding the dremel has made life sooooo much easier it carves into plaster like butter.
Once the carving is done in the plaster tile the plaster dust must be cleaned out or it'll effect the imprint of the clay stamp were going to make. A ball of clay is rolled and flattened with pressure over the carving and a handle is attached... for easy stamping later.
* Bisque firing the stamp - generally before undertaking (the transfering and carving in these few steps above.... ) shrinkage is considered, the size of the C is increased the same percentage as the clay body shrinkage because in all firings clay bodies shrink and with each temperature a different rate of shrinkage... still with me? But seeing I'm fast tracking and am reasonably skilled enough I've cheated a little and made the tile the same size as the photocopied image; making the stamp and drying it off a little in the kiln to harden just a little and then carefully stamped into the clay.
Final result, C sanded and ready for bisque firing.