Digital printing is a fabulous technique: it has recently opened up a whole new world of possibilities for graphic reproduction. Although highly sophisticated, this method still requires certain criteria to be met at the design stage to ensure that the result lives up to expectations... Rest assured, it's not rocket science.

For explanations, please see below.

The format

It's impossible to overlook the notion of format when you're involved in the world of graphic design. This is the wording that follows the name of your file (for example, mywonderful_image.extension). Several options are available: .jpg for still images of reduced quality, .gif for animated images, .mp4 for videos, etc.).

In Print on Demand, the format that interests us is .png.
There are two reasons for this: firstly, because it offers the best possible image quality, and secondly, because it is the only format that supports transparent backgrounds, which are essential for a clean print result.

But wait, what do you mean by a transparent background?

Transparent background

The background of your design is the background of your composition. It has no real use, especially in Print on Demand where keeping it will give a rather unsightly effect once your design has been printed...

A sort of raw border, as you can see here:

To avoid this, you'll need to use the image format mentioned above: .png. Once transparent, depending on the tool you use for your graphic design, your background may be visible as a grey and white grid, but don't worry: it won't be visible in its printed version!

Quality

Nobody wants a product that looks like a screenshot of a game of Snake on an old Nokia. If the resolution of your visual is low, that's exactly what it will look like. A good pixel is one that you can't see.

It is therefore advisable to reserve the best possible quality for your creations, using a resolution of at least 150dpi. In terms of dimensions, plan on at least 2000px for the longest side of your design.

Don't be afraid to think big!

CMYK colours

Do you know anything about colourimetry? It's the little name given to the science of colours: it defines the spectrum, i.e. the range of colours visible to the human eye, which can be translated - or not - depending on the medium.

Some surfaces will reflect the image of certain colours... And others won't! Otherwise, it would be too simple.

Screens reflect colours belonging to the RGB profile (red, green, blue). All the colours we see are mixtures of these three shades. Printed media, on the other hand, have their own colour profile, CMYK (cyan, magenta, yellow and black).

Contrary to appearances, the RGB profile we see on screens is broader than CMYK. It includes fluorescent colours, for example. Unfortunately, these colours, like all those not included in CMYK, cannot be printed... And there's nothing you can do about it: if you try to print them, the result will be dull and hardly comparable with the original.

So three pieces of advice:

• Avoid neon colours at all costs;
• Work directly on your design in CMYK profile to avoid unpleasant surprises;
• If you haven't understood anything in this paragraph, go and read the article we lovingly wrote on the subject

Sufficient contrast

Contrast is another decisive factor in the overall quality of your customised product! It's the degree of difference between the light and dark elements of a set.

Without sufficient contrast between the substrate and the design, legibility is severely compromised, and neglecting legibility literally means denying understanding to anyone who comes across your product. A bit of a shame, don't you think?

So, respecting the contrast between your choice of product and your design means not trying out monochrome concepts of black print (or too dark a shade) on black textiles or, on the contrary, white (or too light a colour) on a white substrate. It's original, all right, but if it's rare, it may be because it's simply not suitable...

If you want to check this aspect of your design, there are online tools for comparing the contrast of a colour with its background, such as this one or this other one.

They are initially designed for web use, but you can use them to check the contrast between your design and the background. https://colourcontrast.cc

https://app.contrast-finder.org/?lang=fr

Do not use semi-transparency

In design, semi-transparency is what lies between opacity and total invisibility (also known as transparency, which is what we talked about above for your background).
Depending on its degree, it allows you to see more or less of the colour just below it. This semi-transparency is used to give relief and a textural gradient effect to an ensemble.

Set against a transparent grid background (as mentioned above), this semi-transparency will look like this:

In some cases, its use is appropriate, but you should be aware that elle is not suitable for digital printing. This (brilliant) printing technique reproduces solid colours using concentrated pigments that cannot be diluted...

Basically, you either print or you don't, but there's no in-between!

What's more, for your print to hold and be visible, a white base is used as the first layer: if the top layer (the colours) contains transparent parts, this base will inevitably be visible and won't give a faithful rendering of the original. Unfortunately, this constraint is unavoidable. So we ask you to ensure that your designs do not contain any semi-transparent elements...

Or, if they do, to remove them! I promise, your designs will look great without them.

How do I know if my design contains semi-transparent elements?

In your design tool, add a coloured layer (grey, for example) and drag it under your visual. If the red is visible through certain areas, then it contains semi-transparent elements. Similarly, if you can see the grid appearing in certain areas, the visual contains semi-transparency.

If you absolutely insist on a transparent effect, we recommend using half-toning.

There aren't many of them, and they're easy to follow, so make some noise for...
The ultimate rules for getting a good impression of your designs:

• Save your design in .png format;
• Use a transparent background;
• Use a minimum resolution of 150dpi;
• Allow a minimum of 2000px for the longest side of the design;
• Avoid neon colours;
• Work in CMYK;
• Pay attention to the contrast of your design;
• Avoid micro-details
• Avoid semi-transparent elements.

IMPORTANT: on white garment, the white of your design file will never never be printed.

You cannot therefore send an all-white logo on a white product: nothing would be printed.

Similarly, on a black textile (black only), the black of your visual will not be printed: these are the only two exceptions, in which case the textile replaces the colour.

Finally, avoid micro-details: small dots, lines that are too fine, small characters just a few millimetres wide may not be printed correctly.

Even if our printers enable us to reproduce your visuals very precisely, textiles are less defined than a sheet of paper: these micro-details may therefore not appear properly, so bear this in mind before sending your visuals.

For more information, there is an article at your disposal:

Preparing your visuals, a bloody important step to ensure top-quality printing