First we will discuss how to remove printing/painting/emblems from a ceramic coffee cup, and then we will show how to put on whatever WE want on the cup.
Step 1: Evaluate the Cup and Gather Tools.
First off, safety first ! There is going to be flying debris, tiny pieces of ceramic, glazing, and paint, some of it in powder form.
So first I put on my safety goggles. Secondly, I placed a fan to my right and one fan in the window to my left (configure them as suites best in your room), the one to my left in the window, was set to draw air to the outside, while the one to my right blew directly over my work area.
I found my dremel and placed a sanding wheel on it. Later, I found that it was better to start with a course "stone" wheel, and then, once all it removed, touch it up with the sanding wheel.......it took too long, and wasted too much sanding paper to use those at the start.
The paints and coatings I used were the type that required curing by baking (350 o F or 177 o C for about 30 minutes).
Step 2: Actually Removing the Emblem, Etc.
My dremel rotates counter clockwise, which was another reason I chose the ventilation direction I did. Facing the spin of the stone so it would shoot most of the debris to my left, a good portion would be on it's way toward the window exhaust fan.
Go slowly, and don't rush the removal process. If you press too hard, you may chip or crack your mug. And no one likes picking pieces of sharp ceramic shrapnel out of their arms or other appendages.
I personally worked from left to right, but I moved the stone from right to left. Personal preference, do this as you feel comfortable.
As you can see in the last picture, the stone completely erased the entire symbol and wording. Most of the glaze was still there also, as I believe it was "printed" after the cup was initially glazed.
Step 3: Stencil Construction and Positioning
Once the emblem and wording were removed, I lightly sanded the area I wanted to place my emblem (or wording if you choose). A damp cloth or tack cloth rubbed over it a few times will remove the last of the dust.
Taking the advice of one crafter, I found some old contact paper to use as a stencil, and drew my emblem onto the stencil.
I then took my craft knife (gift from a friend) and carefully cut out the emblem trying NOT to make any connection points TOO thin (this happened with my second emblem (DD), which I don't show as finished as it did NOT turn out. Removing the backing so you can stick the contact paper to the cup where you wish to imprint it, was much too difficult for small frail connections, and it just tore up on me.
The symbol I DID get to come through, worked out rather well (I think).
Anyway, I removed the backing, and positioned it on to the cup smoothing it out and removing crinkles and bubbles as I went.
Once the template was on the cup, I gingerly painted the exposed area, dabbing rather then "brushing" so as not to get any under the stencil.
The third picture shows what it looks like after I finished.
Notice on the back side of the stencil (picture one) how I extended my lines past where I wanted them to go. This helped me make sure I had everything aligned properly.
Step 4: Preparing for the Oven - Finishing Up
The paint will end up drying in an hour or less if you haven't coated it on very thickly, so make sure you remove the stencil carefully, before this happens.
The stencil is likely to pull up your efforts if the paint completely dries before removal (or at least portions of it) as I show in the first picture. Also shown in this first attempt is the fact that I didn't get the stencil down tight against the cup in a few places and I did a bit of "brushing" rather then dabbing.
After a few minor corrections, I set it aside to dry for about an hour (according to the instruction on the paint). And then coated it with a final clear coat, and allowed IT do dry.
After the hour, it was ready for the oven. This time of year it is much too hot to fire up the gas oven for this, so I settled for the toaster oven, which had the proper temp and time settings for me. The paint instructions requested that, once the oven was off, to allow the cup to cool on it's own before moving.
It didn't come out looking like a factory made cup, but I didn't really WANT it to. I wanted it personalized so it would not get mixed up with everyone else's cup at work.
I didn't show this, but I also signed the bottom (since it was concave, and wouldn't mess up whatever I sat it on).