Reproducing images in colour is often a major challenge for photographers or artists who wish to publish a collection of their creations. Undertaking such a project requires rigorous preparation where no detail can be left to chance.

In a previous article, we showed you that it is impossible to get an identical result on your computer screen and on paper. In short, you’ll need to look into the conversions between the different colour profiles of each tool you use in order to maintain consistency between medium.

In this article, we will offer you a method to get the results you want. This series of articles has been undertaken not only to help you free yourself from these technical constraints, but also to master them.

Start Off on the Right Foot

To publish a quality book and to showcase your various creations on paper, you can start by integrating the best practices into your work routine today. When you address colour reproduction early on in your process, you will achieve better results.

Should you Shoot in sRGB, Adobe RGB . . . or RAW?

You may have already chosen the colour space you’re working with on your camera, either sRGB or Adobe RGB. The sRGB space might be more restricted, but it has the advantage of being used by most devices (monitors, tablets, phones). It is the default profile for JPEG files. About 99% of displays use an sRGB profile. Since an sRGB display only displays 76% of the Adobe RGB space, you might conclude that it is better to choose the Adobe RGB space. Well, it’s not that simple!

If you shoot in RAW* format, it doesn’t matter which space you choose because a colour space conversion will be applied to your RAW file when it’s imported to your processing software. With Lightroom and Photoshop software, your photos will be imported in the colour space used by Adobe ProPhoto RGB, which is even wider than Adobe RGB. If one day, technology allowed us to obtain a wide gamut printer-paper combination and maybe even PhotoPro RGB monitors, then RAW would allow you to rediscover nuances that you never would have seen in your images. In fact, there is more information in your files than you can see on your computer screen. Failure to see a colour does not mean that it’s not in your file, but that you are unable to see it.

*RAW file: uncompressed and unprocessed image data captured by a digital camera or scanner’s sensors. Shooting in RAW captures a high level of image detail, with large file sizes and lossless quality. The direct image data means that you start with a high-quality image that can be edited, converted and compressed in a non-destructive manner.

Source : Adobe
In short:

  • If you shoot in the sRGB space, your images will immediately be in sync with almost every monitor, tablet and smartphone.
  • If, instead, you choose the Adobe RGB space while your monitor is in sRGB, your images will seem dull. You would then have to convert your RAW files to sRGB, which seems absurd.
  • In any case, a meticulous photographer should always use the RAW format.

Image Processing

After shooting, importing photos into a computer is the second major step in the process of publishing a colour picture book. It is very important that you have some mastery of the tools to make technology an ally in your project.

Source : Apple

To better understand gamut differences, you can use Apple’s ColorSync tool to visualize the different colour spaces (or apply an ICC profile if you’re using Windows). By comparing the Adobe RGB space with the sRGB, you will immediately see that the former is the largest and notably contains a significantly richer range of greens and reds than the latter. With this tool, you can also compare the gamut of your monitor with the one of your selected papers. You will notice that they don’t all have the same colour reproduction capabilities.

How to Choose the Right Monitor to Process Your Images

The sRGB space allows you to display 2.5 million colours while your eye probably only perceives a million, as is the case for most people. If you frequently do fine art prints and can afford it, you can, of course, invest in an Adobe RGB monitor, since this colour space is actually more similar to the space of inkjet presses.

The Adobe RGB space helps display more saturated colours in greens and reds. The question you must therefore ask yourself before investing in an Adobe RGB type monitor is: Do you need to visualize images containing these particularly saturated colours? If, for example, you are photographing models who are wearing dresses made with particularly saturated coloured fabrics, you will need to consider purchasing a monitor that uses the Adobe RGB space. If, instead of printing your images on inkjet printers for fine art, you mainly distribute them on the Web, the sRGB is quite sufficient.
In conclusion, a sRGB monitor is very good! An Adobe RGB monitor is significantly more expensive and if you do not fully control the graphic chain, it may be better to spend your money elsewhere. Generally speaking, it is best to rely primarily on your skills rather than the quality of your equipment.
Tip: It is best not to use your laptop to work on your photos, as this type of computer screen can be unstable and usually only has a very narrow viewing angle. Depending on its inclination, you won’t see the colours in the same way. You can, however, use your laptop to sort your photos.

Calibrating Your Monitor

The calibration of your monitor is the keystone of your graphic chain. Your monitor should be your reference for the rest of your work.

A monitor’s calibration is used to measure the colours it is able to reproduce. Calibration is also used to identify the colorimetric drifts of your monitor. Because, even if you acquire a high-end monitor, differences will evolve over time, which is why you need to calibrate your monitor regularly.

To calibrate your monitor, you need to purchase a probe. It will allow you to create the ICC profile of your monitor. There are very good probes at affordable prices. In fact, their cost has been divided by about 20 over the past fifteen years. We recommend to use a spectrophotometer*, first because it is much more precise than a colorimeter* and second because it is not very expensive. The X-Rite i1Display Pro, a benchmark in the photography world, costs around US$250 while a similar, smaller model, the X-Rite i1Display Studio Colorimeter, costs US$170. Such a small price difference may not justify depriving you of additional precision.

Source : X-rite

*Colorimeter : a tristimulus colour measurement tool that provides an objective evaluation of colour characteristics based on the light passing through the primary filters of red, green and blue. It simulates how the human eye perceives colour.
*Spectrophotometer : a more complex colour measuring instrument that factors in the light intensity as a function of the colour. It performs a full-spectrum colour measurement, as opposed to a colorimeter’s tristimulus procedure, and generates colour data that exceeds what the human eye can see.

Source : Datacolor
If you strive for perfection and also wish to calibrate your printer, the spectrophotometer will be, by far, the best option.

How Often Should You Calibrate?

Depending on its quality and age, your monitor will need to be calibrated more or less frequently. A good monitor needs to be calibrated at least once a month, and more often if you have a lower-end monitor. Professionals even do it every day.

What Is an ICC Profile Used for?

Source : Wikipedia
The ICC (International Colour Consortium) profile is a reference system where the table shows both the values your equipment is capable of displaying (the gamut) and the corrections for its drifts. Some say it is the equipment ID card. This file will allow you to translate the coordinates for each colour of the source space—in this case for your monitor—into data encrypted in the L*a*b reference standard. The printer driver will translate the requested colours with this table into an identical or a similar colour according to its own gamut.
Source : Wikipedia
In Canada, we understand how a translation between two languages can have unpleasant consequences. The same can be applied with colour since you have to avoid losing information between the conversion of the original file and its reproduction on paper. In this case, your best translator will be the ICC profile that you will generate once the calibration is completed.

What’s the Difference Between a Colour Space and an ICC Profile?

A colour space is a reference, independent of equipment. There are four of them for photography, which are the sRGB, the Adobe RGB, the ProPhoto RGB and the L*a*b space. An ICC profile is a colour space that integrates the colorimetric characteristics of a camera, a monitor or a printer-paper combination. It’s qualified as dependent.

The Main Colour Spaces in Photography

The colour spaces we talked about, sRGB, Adobe RGB, ProPhoto RGB and the L*a*b space, fit together like Russian dolls. Ranging from the sRGB which is the smallest, to the L*a*b which is the largest.

Source : PH Learn
Little clarification on the respective sizes of the spaces: Adobe RGB monitors never cover 100% of this space, its coverage is around 97%, while the sRGB’s is 76%, which does not mean that 24% of the colours in your photos will be lost, because these values are, in fact, not used very often. Your photos don’t necessarily contain every colour of the rainbow.
If you’ve invested in an Adobe RGB display, here’s precisely what’s going to happen before and after your file prep work:

  • If you work with a digital camera set to sRGB and you have chosen the RAW format, you know that your photos will be converted to ProPhoto RGB when imported into Lightroom or Photoshop. Current monitor technology does not allow ProPhoto RGB to be displayed;
  • If you export your images to a printer who uses a narrower colour space than yours, the more saturated colours will be converted to less saturated ones;
  • If you print on an 8, 10 or 12 colour inkjet printer, with a relatively larger gamut, you will get more saturated colours than the printer’s four colour press.
If you work with a sRGB monitor and entrust your prints to a service provider who exclusively uses the Adobe RGB profile, you can very easily choose this space when exporting your file without any quality loss.

An Example of Conversion From one Space to Another

To better understand the conversion process, let’s do a little demonstration with the most saturated green and take a look at the attached diagram. The top tip of the sRGB triangle (in the green area) has the same RGB values as the top tip of the Adobe RGB triangle. Yet, the green at the tip of the Adobe RGB triangle is noticeably more saturated. The differences for red and blue are less important, but they also exist. If you work without an ICC profile and switch between spaces without conversion, for instance from sRGB to Adobe RGB, you will get random and, therefore, disappointing results. By using an ICC profile, you might get a greenish yellow, but you will stay in control, because you will reproduce the most saturated green possible in the sRGB space.
Here is an example: the 0R, 255G, 0B value of the Adobe RGB space will correspond to the tip of the triangle (the greenest colour) and corresponds to the 0R, 255G, 0B value of the sRGB space’s upper tip of the triangle. So you understand how RGB values are not a reference point if you do not associate them to a colour space.

To sum up, there are three scenarios when creating a file for printing:

1. The visible colour on your monitor is included in your printer’s colour profile. This case is very simple to manage, because the colours are identical. This is what happens in most cases;
2. The visible colour on your monitor is not part of the colorimetric space that can be reproduced by your chosen printer-paper combination. In this case, the ICC profile will establish the best possible match with the closest colour on your printer (also read the frame below “Rendering intent: relative or perceptive?”);
3. The printer-paper combination contains colours that are outside your monitor space, this is particularly true for green colours. In fact, the colorimetric space of the printer-paper combination is much more complex than the one of a monitor. Check it out with Apple’s ColorSync tool (or by applying an ICC profile if you’re using Windows). Why tell you about this when your image does not contain these colours? On one hand, because it is a reality that you must know, and on the other hand, because if you carry out tests with different images using several types of paper, you will find that some are better to reproduce certain colours. For example, you could use a different paper for landscape photos, since the colour green usually occupies a larger part of the spectrum. Test it out and you will see!
The red shape in this diagram represents the space of a Graphic Art monitor close to the sRGB, while the green shape represents the space of a printer-paper combination (glossy paper).
So you see that you will have to compromise when printing. It will take a few tries, but you will learn a lot more about the art of printing than if you relied solely on the capabilities of your equipment or the “superpowers” of your printer. Over time, you will even save money by obtaining a satisfactory result on your first try.

Rendering Intent: Relative or Perceptive?

If you work with Lightroom or Photoshop, we think that it’s important to mention the rendering intent. To put it simply, remember that if you choose the perceptive mode, Lightroom will convert your workspace colour to the workspace of your printer while making sure that the adjacent colours are consistent with it. However, in relative mode, Lightroom will only do a one-time conversion for each colour. This second technique can sometimes create an unpleasant edge effect. Depending on your artistic sensibility, and for certain types of images, you may still prefer the relative mode.

Rapido’s Additional Tips

The higher your expectations for colour reproduction are, the more you’ll want to build an efficient workflow. Files produced rigorously will always produce better results than when adjustments are made at the end of the process. By increasing your control over the colour reproduction, you’ll have a greater mastery over your creative work. For instance, this is what we made sure of during our collaboration with the professional photographer Pierre Gauthier, whose black and white photo album enriched in a four-colour process required special care.

Pierre Gauthier
To publish an image on the Internet: we recommend that you always use the sRGB profile when exporting. If not, the browser will take care of converting it for you and the quality of your image could be affected. The Lightroom and Photoshop export modules allow you to save all your export settings, which is very convenient to ensure that your images always include the same exportation settings.
Take care of your working environment: work in an environment where the light is stable. The best option is to close the curtains and turn off all the lamps that are within three meters of your monitor. The author of these lines works almost in the dark and preferably very early in the morning as to not be disturbed by people turning the lights on in the room.
Pay attention to the background colours of your monitor: favour a black close to a value of 50%. Also, do not install your monitor in front of a brightly coloured wall, as this will influence your vision. To better understand, put down two squares of the same colour, one on a gray background and the other on a red background. You will realize how different your perception of colour will be.
Books printed by Rapido

Conclusion: The 4 Golden Rules of Colour Image Processing

As you can see, nothing can be left to chance when it comes to moving your images from digital to paper. In this article, we gave you many tips for each step of the process. If we had to name only a few, here is a reminder of the essentials:

1. The first parameter you must tackle is the DHP. Don’t look for it in the print menus, you won’t find it. It is well hidden, somewhere in your brain. The DHP is the “damn human parameter”! It essentially feeds on our prejudices and prevents us from progressing. How can you have control over it? By training, getting information and reading articles on the subject frequently. The Web contains so much information, tutorials, forums and online training, you will always find what you are looking for.
2. Be sure to calibrate your monitor before processing your images. If you process your images without calibrating your monitor, it’s similar to crossing the Atlantic with no compass. Have a good trip!
3. Remember that everyone perceives colours differently, and the same applies for all equipment, they always have their own colour space. If you think that your printer will figure it out on their own to reproduce the result you are hoping for, you might be disappointed!
4. Harmonize your equipment. To succeed, you will have to harmonize the different colorimetric spaces of your graphic chain, such as:

  • your camera if you are a photographer;
  • your computer screen;
  • and your printer or printer’s press.


Does your project raise more specific questions than those addressed on this page?

The answers can surely be found in our complete printing guide. Click here and download your free copy:


Want to get off to a good start in creating your print files?

Find the main properties to respect in this JOBOPTIONS file that we have specially prepared for you: