Printer Profiles – A Deep Dive

Printer profiles are a seemingly daunting and complex topic - they have been discussed and dissected millions of times, and yet, what they are what they do still confuses people across our industry. The reality is that printer profiles are a lot less mysterious than most people think, and every print shop in the world is using them whether or not they are aware of it. This article provides a bird’s eye view of the profile creation process, and from it you will gain an understanding of why you should invest some time and perhaps money into developing your profiling skills.

What is a printer profile?

A printer profile is a collection of settings that determine how and what our printer prints. It is used by a driver or a piece of software called a RIP and is often provided by the manufacturer of the material or the reseller who supplied the material. Materials do have different physical properties and a printer will have to adjust its settings in order to achieve the desired results.

It’s important to note that printers can start printing differently over time. When this happens, it is the printer itself that starts to drift and not the profile. Printer profiles are static, which means that they don’t change. It’s like taking a snapshot for a new passport photo - it makes sense to renew it every 10 years or so, not because the pic got too old, but because faces change. The same occurs with printers, materials, and ambient influences that might alter the printing results.

What do we need to create our own printer profiles?

Color patches are being measured by a color measurement device

Firstly, profiling requires a color measurement device, preferably a spectrophotometer. Spectrophotometers are devices that contain a calibrated light source and a sensor that captures the reflected light from the material. This sensor converts the reflected light into a digital waveform, known as “spectral data”. Depending on the type of material you are measuring, you might need specific tools for the measurement device. Think of fabrics, which might warp or have an uneven surface that scatters the light. We will cover the different measurement devices on the market today in more detail in another blog post, but for now, suffice to say that measurement devices come in all shapes and sizes. They range in price from $1,000 to $15,000  and are configurable with many options. Contact us if you want to know more about what is available or which ones we use in our labs.

Besides a measurement device, we will also need software to analyze the measurements and calculate the adjustments needed to get the desired output. All RIP software do have the capability to perform at least 4 of the 5 steps listed below. The 5th step requires the software to have the ability to create the so-called ICC profiles, but more about that later. Some RIP softwares do have their own ICC creator, others require you to have a 3rd party software solution. The most famous 3rd party ICC creator is the i1 Profiler, which is made by X-Rite.

Profiling, Step-by-Step

The creation of a printer profile consists of 5 individual steps, some of which can be skipped with certain printer models (we will discuss this later).

Step 1: Preparation

The first step is probably the most obvious one: make sure the printer is working properly and handles the material such that it performs optimally. Every printer has manual or automated processes to ensure all its print heads are firing, and to compensate the material feed for the material thickness. Make sure to check (and double-check!) these settings, since there is no profile or software magic that will be able to fix misfiring, clogged, or misaligned print heads.

Once everything is set up correctly, it is time to start thinking about what we are trying to achieve. High quality, high print speed, or a mix of both? High quality often means a lower speed, and vice versa a higher speed will cost quality. As a note, most profiles that can be downloaded from the ColorBase Profile Search tool are a mix of speed and quality - the sweet spot for most printing companies.

Step 2: Ink Restrictions

Once we have determined our print priorities, and ensured our printer is running smoothly, we have to verify that the printer is laying down correctly calibrated ink amounts. The first step of this process is to make sure that all ink channels are restricted to meet the desired target. Most RIP software will set the target at the point where the dark colors (cyan, magenta, yellow and black) reach the ‘tipping point’. This tipping point occurs when adding more ink starts to cause image quality issues, or no longer adds any additional color and only makes the print darker. Most RIP softwares also use the measurements taken during this step to set the light ink amounts and light ink mixing levels. It’s important to remember that 100% light ink is as much liquid as 100% dark ink and since we are fighting ink amounts here, it is critically important for the light inks to be set correctly.

As you are probably beginning to see, ink restrictions are a giant topic all on their own. Most RIP software will set them automatically with good results, but there are a lot of great tricks you can play once you have an advanced understanding of the mathematics behind them. Let us know through the poll below if you want to know more about them.

Step 3: Linearization

After the ink restrictions have been set, and we have found a new 100% for each color channel, and the dark and light inks are mixed, we are ready for the next part of the process: making sure that each step in between the material color (0% ink) and the maximum ink amount (our new 100%) prints correctly. This is fairly simple: the RIP software generates a chart with multiple steps for each ink color channel. Note that this chart looks almost the same as the one we measured in step 2, but this time the ink channels are clipped to the new 100% values we found and the light inks are mixed into the dark inks. Most RIP software produces a chart that contains 20 or 33 steps per color channel. By measuring each step and comparing the values to the target, the software calculates the correction it needs to make in order to reach the desired target. Imagine that our target is to get a linear result, this means that when we ask the printer to print 50% of a certain color, it will print enough ink to produce 50% on the material. This sounds easy, but keep in mind that materials absorb ink (and some more than the others). Also aging of printheads and changes in environment will have an impact on how inks dry up. For that reason, it is recommended to linearize the printer regularly.

Some printers do have built-in measurement devices that are capable of performing this calibration all by themselves. There is no guarantee that this will work as well as an external measurement device, especially when calibrating materials with uneven surfaces, such as textiles, mesh banners, or anything transparent or reflective. We are planning another Deep Dive article about the profiling of transparent and backlit material. Keep an eye on this blog!