Step-by-step guide on how to check custom printed paper cup graphic design, colours and proofing

1. Checking technicalities

Go through all the guidelines in all pages of the relevant branded product template

Usually, these things look like below (example). Check each of them step-by-step.

Prepare a single, open, editable .pdf vector file with the artwork on a single separate layer.
All essential graphics must be placed within ‘safe area’.
The background of your graphic design should fill the whole ‘printing area’.
Bend logo and texts according to the guideline grid, otherwise straight texts will look bent up on the cup.
All graphics used in the graphic design should be at least 300 dpi quality.
Place all graphics within the file, do not link them.
Convert all fonts to curves.
Do not use lines thinner than 1 pt. as they might differ from screen appearance.
Be careful with small text below 6 pt. as well as tiny symbols like ©, ™, ®, etc., as they might not be readable.
For the deep black colour used on the uniform-colour background, please use C30 M30 Y30 K100.
Note that small differences (up to 20%) between colours may be hardly visible on a final print.
Use only CMYK colours. Colours from other spaces, such as Pantone, RAL, etc. will be converted automatically to CMYK and the results of such conversion cannot be the basis for a complaint.
Consider that different patterns as well as horizontal lines running around the cup may not join together on the vertical seam of the cup. Vertical displacements can be up to a few mm.
Due to the difference in the paper used, the white colour and its temperature of the outer layer of the cup may differ from the inner layer, wrapping and sealing.

2. Checking colours

Colour science is a complex matter

Colours evaluation is a very tricky subject as it depends on: how we perceive the colours in our mind (it processes it, depending on neighbour colours and patterns), our age (older people tend to see colours more warmly), how many types of colours receptors we have in our eye (usually everyone has 3, but there are some people that have 4 or 2). In the case of printed proof, it depends on the printing technique, printing substrate (type of paper, or transparent plastic), and light source (as we see the light reflected from print). In the case of transparent plastic cups this also get complicated as printed colour depends on the colour below it (like white background added for better reflectivity) or the colour of the drink poured in the cup. In the case of evaluating colours using computers things get even more tricky as 99% of computer screens are not able to view the printing colours (they are outside their colour space). Printing technique is also very important subject as colours defined in CMYK are not definitive ones but rather only the proportions of inks to be mixed. On top of that, there are printing and production tolerances, so the colours on the final product may differ by +/-15% from the design values.

It is really worth to take a while and read basics on Wikipedia on colour space, colour and colour vision generally.

In a perfect world everything shall be calibrated, but in reality, working with the customer at a distance is really hard to do, and often even impossible as it outweighs the price of the product itself. So even if you get all the acceptance of graphic design from your customer, when it comes to the final product, you may face a colour-based claim, as they might have evaluated colours in the first place in a very improper way.

Colour proofing

Below, we will list some limitations associated with different types of proofing techniques.

In the case of a SPR – calibrated printed proof (calibrated print), there might be colour deviations due to differences in printing technology and substrate used (type of paper), as well as the type of light used to assess it. Natural daylight or calibrated light source shall be used, otherwise evaluating colours in artificial light can lead to mistakes like for example brown could look violet. Some papers reflect light different way than other, and similarly, some papers soak inks much more than others, which impact the colours as well. Calibration helps to mitigate some of these problems, but it is not perfect. So when you have a big order and a client sensitive to their corporate colours, this is the best way to evaluate colours.

In the case of a printed proof (uncalibrated print), there might be colour deviations due to differences in printing technology and substrate used (type of paper), as well as colour reproduction by your uncalibrated office printer or online printing house. On top of that, we shall add everything that was said before regarding the light and paper. Do not expect to get what you see.

In the case of digital proof (calibrated computer monitor), colours will be different due to different colour reproduction of your monitor (emissive vs reflective), often lack of proper configuration of graphic design software or lack of up-to-date calibration. Monitors also use an emissive light source, when the print is reflective. Computer monitors to cover for CMYK colours space have to have 99% AdobeRGB or DCI-P3 colour space coverage. These monitors are referred to as a wide gamut, and many vendors have for them other marketing names like dreamcolour or other. Nevertheless, do not expect to get exactly what you see.

In the case of digital “proof” (standard computer monitor), colours will be different due to the different colour reproduction of your monitor, and the limited colour space they can reproduce. On top of that, they lack any calibration of the monitor and the software. Monitors also use an emissive light source when the print is reflective. Print colours are impossible to show on sRGB monitors, as their colour space is just smaller. Using such a setup for evaluating colours is the worst idea of all, simply do not expect to get what you see.

The main purpose of any proof is a general assessment of the graphic design, elements distribution, size and correctness of the texts, but it will never reflect the final print in 100%, especially colours.

So make sure your customer understands all of that, and no shortcuts were made in explaining that to him. Otherwise, you may face customer claim.

Answering a question, if we can do just a small test run, just a few pieces of your branded product to evaluate colours? It is yes, and no.

Due to how our production is organized, it would cost you the same as MOQ (minimum order quantity), so often it is the same as ordering 1000 customised paper cups, so we simply do not do it separately. Please also notice that our print techniques change, so when you are ordering 1000 cups and 100.000 cups we use different one, might having impact on colours as well. But there is another way to check how the design will look on a cup – see above (scissors and tape).

Are you afraid that the colours in print will work the way you want them to?

Order a sample printout (SPR) – a printed proof, which is a calibrated digital printout simulating the colours of the final product, and look at it at your place in various lighting conditions. Be aware, however, that minor deviations in colours are still possible due to the use of different paper and printing techniques, but still, it is a much better method of colour evaluation than looking at it on an uncalibrated computer monitor with limited sRGB colour space.

3. Checking placement and size

Wondering what your chosen bespoke printed product will look like?

Order the product visualisation (VIS) service and we will prepare it based on a ready-made graphic design, which you will provide us with. It is a 2D render of a 3D model with your graphics on it.

Branded paper cup graphic design on rainbowcups’ template

Visualisation (3D render)

Final product (real picture)

Other examples of custom printed paper cups visualisations (VIS):

4. The best way overall to check the branded paper cup graphic design

Take the tape and scissors in your hands!

Simply order SPR (calibrated sample printout), or alternatively print without scaling the graphic design from the rainbowcups template in 1:1 scale (but you will not able to properly evaluate colours). Cut it out with scissors along the cutting line, and tape the sides together to form a cup without a bottom. Put in on existing white cup or other paper cup sample.

Consider that different patterns as well as horizontal lines running around the cup may not join together on the vertical seam of the paper cup. Vertical displacements can be up to a few mm resulting in a different outcome than anticipated (see the example beside, it is sewing, but the idea is the same).

Then check that all texts and logos are the right size and in the right places and that they are bent in the right way. Check that the texts and logos are clearly visible and not distorted (or properly distorted). For example, due to paper cup geometry (it is a flipped upside-down cut cone), if you want the logo or text to be straight on the cup it has to be bent on the design to the yellow grid. By leaving a straight line or text on the design it will be perceived as a curve.

Take in mind that due to the difference in the paper used, the white colour and its colour temperature of the outer layer of the cup may differ from the inner layer, wrapping and sealing.

Check everything under the daylight and make sure you are 100% satisfied with the result and are aware of possible discrepancies regarding the placement, distortions and colours. Check twice all texts and graphic elements, as we will print exactly what you see.

Make sure to do all of that before finally accepting the graphic design, because after it hits the production, it is already too late.

Make sure your customer is well-educated on the above matter and understands all those issues, nuances, has realistic expectations, and has checked the graphic design in the proper way, otherwise you can be in real trouble.