My digital images come from the Internet and have a resolution of only 72 dots per inch. Can you reproduce them well on your sublimation mugs?


Although we can use low resolution images (such as those downloaded from Internet web sites, for example) for decorating coffee mugs, the results might not be acceptable at all to you.

As described elsewhere in our web site, raster or bitmap digital art should have a resolution of at least 300 diary planners  (pixels per inch). Raster art files of 72 dpi’s can easily be up-sampled to any desired resolution – however there is always a loss of image quality.

Maybe we can best illustrate this with the following example of an internet down-loaded image with a resolution of only 72 dpi’s:

Original downloaded digital art:

– size of original image: 3″ x 3″ at 72 dpi’s: 3x3x72 = 648 (this is just a number representing the “contents” of this image);

Up-sampled art:

– size of image: 3″ x 3″ at 300 dpi’s: 3x3x300 = 2,700 (this is the new “contents” of the same, but up-sampled image).

For the computer to create a high-resolution image of 300 dpi’s it had to “guess” the “missing” pixels between what was given to it, (the original image with only 648 contents units) and create out of these 648 a high-resolution image with a “contents” of 2,700 units.

The computer did this by extrapolating (guessing) the non-existing pixels and then “add” those computer-generated or guessed pixels to the high-resolution image to be generated, based on the computer’s best guess or estimate of what the “old” and the “new” image is all about.

You can imagine that the result is not what you’d expect: namely a high-resolution copy of your low-resolution original. All you get is a high-resolution something that has very little to do with your original.

Basically, the more pixels you have, the sharper your picture is going to be.

For comparison, a regular, old-fashioned 4″ x 6″ photo tends to resolve at about 12 million to 15 million pixels (mega) and a digital photo to about 2-3 million pixels (for a 2-3 Meg camera, for example). Thus, it’s not surprising that a digital artwork with only 72 pixels per inch will not print with the same sharpness as your regular, conventional photo… and this is the quality we aspire to and can print on our sublimation coffee mugs…almost like the old-fashioned photos, except on white coffee mugs.

The ONLY way to obtain a high-resolution image is to either re-scan it at the desired resolution or take another high-resolution picture with your digital camera or create a brand new design with your raster/bitmap program and save it at the desired resolution.

Please also note in this context that vector art is not subject to these limitations as vector art – as well as all fonts if used as created by the original program and not saved as raster or bitmap files – can be up- or down-scaled without any loss of quality at all.

Evaluate the difference between vector art and raster/bitmap art.

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