the idea / the object of interest
the idea for this project came from The IT Crowd which is/was a British sitcom. i have just found this video over at youtube which will describe it best.
Moss comes in one morning telling his colleague Roy that he has got a new cup. which at a first sight looks just like every cup in the office. but clever moss put a picture of him on the base, so everyone knows it’s his. but everyone else in this episode is drinking from his cup (without knowing it) but him.
the long story
inkjet decal paper
so when i was looking for “moss mug” and “moss cup” on ebay i sure found some cups which all stated they where not waterproof. but as i was not willing to wash my cup everyday by hand instead of with our dish washer – i was looking for a better solution. also one could easily spot that the cups on ebay where all self-made. so i found out that those surely have been made with decal paper. so i was looking for a solution to make a cup with decal paper but also waterproof. the first thing i tried was to use inkjet decal paper and fixate that with clear paint (spray can). so i cut the inkjet decal paper to size, put it on the base of an old test-cup and fixated it with several layers of clear paint.
it looked quiet good and also got passed several cycles of the dish washer. but then went off after .. i think .. the 6th cycle or so …
laser decal paper
time passed and i always had this project in my mind but couldn’t find any good solution until i met Eva. Eva came to our hackerspace in nuremberg (which is an “open workshop” in Künstlerhaus) as her computer was broke. as she was also part of the Künstlerhaus in an other open workshop .. the ceramic workshop .. i said i would fix her computer if she’d help me with making such a cup. she asked colleagues of her and also gave me several books where i found the suggestion to print the graphics with a laser printer and burn it (i then also found this howto). some laser printers toner consist of iron oxide which survive firing them .. here the image before the firing in a furnace at several hundred degree.
so we did several test runs which all had the same result. the decal and the printing itself where gone after the firing. i therefore assume that the toners i was using did not have enough iron oxide in them.
again some months went by and i stumbled upon a box saying “paint-a-cup” (which be found on amazon) .. turned out my partner bought it five six years ago to create a birthday present …
i instantly tried to think of a good solution to bring my likeness to the base of a cup. for my first tries i printed the portrait twice on an overhead transparency and cut out several parts so that it resulted in two patterns which overlapped made the likeness complete and also would be stiff enough to let me paint easily. it turned out that if the paint once got between the cup and the transparency it spread widely and i couldn’t manage to remove just the not wanted paint. thus i had to clear it completely and start all over again. also it was not easy to remove the patterns as the paint was still wet …
so i thought back of my first tries and remembered that i still got some printed laser decal papers laying around. so i cut them to patterns and folded one edge so that i just had to tip on the edge to easily remove the pattern.
so i started to test again, painted the test-cup waited impatiently for four hours (as intended) and put it in the oven at 160°C for 90 minutes. back in the office i put it in the dish washer every day for a week and the paint still was there.
then it was time to experiment with the colours and i ordered some more cups and another pen and went wild.
i just finished firing them in my oven and also the painting of the pen which said to fire it “no longer than 30 minutes” looks quite good.
TL;DR – the short story
if you want to have a waterproof painting/image/something on a porcelain – use paint or pencils saying “ceramic/porcelain paint”.
if you want to use a patterns take thick paper so if there is too much paint it can be suck by it. fold one edge for easy remove.
here is my result: