UV/Glow in the dark tumblers are coated with a colour changing outer layer, which will change color when placed in sunlight or glow in the dark. UV/Glow changes and cycles are dependent on the intensity of exposure to sunshine and the number of washes. Different cleaning methods (eg. dishwasher) also affect the longevity of the coating. Excessive exposure to sunlight further reduces the lifespan of the coating.
OVEN METHOD:
This method is in my oven which is a thermo fan. If you have any other oven then you will need to test what works for you, its like baking a cake. If you have a top and bottom grill it will be hotter so test with a tumbler first to see how it goes. If you bake to long the print goes dull/light like it fades.
- Preheat oven on 180 for 15min
- Tray must be in the middle of oven or just below
- Put silicone paper or baking paper on try
- Secure print tightly to tumbler
- The shrink film. Slit it down the side then secure it tight to the print, cut it down to size if too long and double tape the join
- Get the heat gun and shrink it to the tumbler, tight, no creases or bubbles, smooth. Don’t put the nozzle to close otherwise you can melt the film, about 10 to 15cm away and wave it around like a hair dryer.
- Upside down in the oven for 6min on 180
- Then take out and remove everything immediately
PS use gloves when taking it out the oven!
Point 5 is the easiest rather than putting it over as it is a mission to remove, here you just pull off the tape and it unravels, what works for me. Make sure where you re-tape the shrink film to do x2 rows of 2cm heat tape as it can pull apart in the oven.
Also please do not let shrink film on to raw tumbler, it can now and then surprise you and stick to the tumbler and then you can’t get it off! Use silicone paper to protect your tumbler but I always use the full paper even if I don’t do a full print that is if you are using a straight tumbler then no silicone paper required, it is only on the old shaped ones.
