1) Keep kids away. I guess the stuff is not poisonous but it stinks like hell! Keep doors and windows open if you can!
2) Use either a sunny day to work with Lumi or use a strong UV-lamp. I tried my 5000K photo lamps first, nothing happend. Best results were achieved on a sunny day.
2) A laser printer is not useful, try to get your hand on an Inkjet that is able to produce a strong black on transparent film. The results we show here were made with 2-3 transparent laser-printed films, stacked on each other. Even then I guess the results are behind a single good inkjet print.
3) Get sufficient quantities of cardboard. If you want to print on a T-Shirt, insert a piece of cardboard into the shirt in such way that the dye does not get through to the other side. Instead of cardboard I also used green and gray LEGO tiles which have approximately the size of an DIN A4 sheet.
4) In addition to the applicator Lumi provided I found paintbrushes really helpful.
After these general hints, let's get started.
I wanted to do something with Lemmings so I got some picture via Google image search, that show the single pixels for various lemmings such as the walking one or the stopper.
In Corel Draw I defined a grid and started to redraw each lemming. Once a single lemming was complete I could copy and paste them easily to get three rows. As i have been working with Corel for more than ten years, this was the easy part.
Finally I printed two copies on transparent film and stacked them with tape. The rest was pretty easy. Take the shirt and apply sufficient Lumi. Place the stacked film on the wet Lumi area and expose to the sun for 10-15 minutes. (It is helpful to cover the parts where one accidentally applied lumi with cardboard)
Finally rinse it using the Lumi detergent and wash it.
I am not very satisfied with the result, the contrast is much to low. Nevertheless it gave us a good understanding what works with Lumi and what not.