… with my new and unique custom printed coffee mug.
How it started
For some time, I’ve been thinking about having a custom printed coffee mug using artwork that I make. On eBay there are many people who will make a custom printed coffee mug for you for a low price (£6 to £9 or so) if you send them the artwork.
I’ve also watched the YouTube videos of people who do this and it’s a popular craft type hobby.
On eBay, for about £300 I could get a hobbyist grade set of new equipment and consumables that would let me make my own and then recover the capital costs after selling about 60 mugs but I don’t want to go that far.
For about £500 I could get some robust ‘semi-pro’ grade equipment.
So, I contacted an eBay supplier who printed mugs with client artwork and ended up with this as an initial simple design:
(Please try to ignore the ‘vertical streak’ reflections of me and other objects.)
Note: I know that the krita logo is the intellectual property of the Krita Foundation but this is a technical experiment for personal learning purposes and the mug will not be sold, hired or loaned to anyone else.
Some technical details
The heat diffusion transfer process, from the CMYK sublimation dye printed paper, is very much a ‘craft’ activity in that it requires lots of experience and has many variables that are particular to the equipment and consumable materials that are used.
I sent the supplier a 20cm x 9cm 300dpi RGB/A sRGB .png image, artwork on transparency, then expected the attainable resolution to be quite a bit less than that, especially when you consider how the dyes get from the printed paper into the coating on the mug and that there are a lot of manual operations and craftwork involved.
I was surprised to see single pixel detail which is obvious to the eye, especially in high contrast areas.
The single pixels you can see have rounded corners and faded edges but are very distinct.
I’m going to contact the supplier to see if they can print at 600dpi onto the transfer paper so that I can get better results for any future mugs.
I softproofed the artwork with a CMYK coated paper profile and the purples and blues were very badly subdued, as expected. So I boosted the lightness and saturation but it was still very subdued on the softproofing. I was surprised at how good the colours did turn out in the end though.
Maybe a special ‘dye sublimation mug printing’ profile is needed.
For future artwork
With hindsight, I think the circular logos may be a bit too big at 7cm diameter. Perhaps 6cm or even 5cm would look better. A small amount of vertical compression might help reduce the apparent vertical stretching effect caused by the horizontal curvature of the mug.
The jaggies on the AHAB logo are terrible and that’s my fault for not paying attention when I scaled my profile picture artwork. I’ll try for 600dpi artwork in future and will ask the supplier about that.
I can even see the gradient dithering which I suspect was introduced by use of ‘pngquant’ or some similar process:
(Zoom in needed to see dithered pixels on the artwork.)
For 600dpi I think a 1px Gaussian blur would give good results. I’ll try it one day soon if the supplier can print onto transfer paper at 600dpi.
I could do a ‘test artwork’ with various features to see how it turns out but the idea of paying for that puts me off the idea.
Templates if you want them
Here are two template .kra files for anyone who wants to try this. The 600dpi one is simply a scaled up version of the 300dpi one. They’re CC 0.0 so you can do what you like with them.
They’re for 20cm x 9cm ‘full wrap’ on standard 8cm diameter 9.5 cm height mugs. They’re easy enough to figure out so I won’t give any further explanation:
Some suppliers say they can do 22cm x 9cm printing but some also say you should put a ‘litle bit of bleed’ at the edges. That sounds strange to me because you can either print 22cm x 9cm or you can’t.