OVEN METHOD
This method is based on the settings I use in my thermo-fan oven. Different ovens can behave very differently, so you may need to test and adjust the time or temperature to suit your own oven.
Think of it like baking a cake — every oven is slightly different. If your oven uses a top and bottom element or grill, it may run hotter than a thermo-fan oven.
I strongly recommend testing with one tumbler first before doing a full batch.
If a tumbler is heated for too long, the print can become dull, faded or too light.
- Preheat the oven to 180°C for approximately 15 minutes.
- Position the oven tray in the middle of the oven or just below the middle.
- Place silicone paper or baking paper on the oven tray.
- Secure your printed sublimation paper firmly and tightly around the tumbler using heat-resistant tape. Make sure the print is smooth and there are no gaps or loose areas.
- Prepare the shrink film. I find the easiest method is to cut a slit down the side of the shrink film, wrap it tightly around the tumbler and trim off any excess length.
- Secure the join with heat-resistant tape. I recommend using two rows of approximately 2 cm heat tape along the join, as the shrink film can sometimes pull apart while heating in the oven.
- Using a heat gun, carefully shrink the film tightly around the tumbler.
Keep the heat gun approximately 10–15 cm away from the shrink film and move it continuously, similar to using a hairdryer.
The film should be:
- Tight against the tumbler
- Smooth
- Free from bubbles
- Free from large creases
Do not hold the heat gun too close, as this can melt or damage the shrink film.
- Place the tumbler upside down in the oven and heat at 180°C for approximately 6 minutes.
- Remove the tumbler from the oven and immediately remove the shrink film, tape and sublimation paper.
Important
Always wear heat-resistant gloves when removing tumblers from the oven. The tumbler will be extremely hot.
Shrink Film Tip
I personally prefer cutting the shrink film down the side rather than sliding the entire shrink sleeve over the tumbler.
Once the tumbler is finished, you simply remove the tape and the shrink film unwraps easily. I find this much quicker and easier than trying to pull a tight shrink sleeve off a hot tumbler.
Protecting the Tumbler
Where possible, do not allow shrink film to sit directly against an exposed or unprinted section of the tumbler.
Occasionally the shrink film can stick to the tumbler during heating and can be very difficult, or sometimes impossible, to remove cleanly.
For shaped champagne tumblers, I prefer to cover the tumbler with paper even when I am not doing a full-wrap print, as this helps protect the surface from direct contact with the shrink film.
For straight-sided tumblers, additional silicone paper around the tumbler is generally not necessary when the print itself already protects the surface.
Please note: These settings are a starting point based on my own thermo-fan oven. Always test your own equipment, as temperatures and heating performance can vary between ovens.
