The CRI (Colour Rendering Index) is a measure of the colour rendering quality of a light source. It indicates how well a light source reproduces the colours of objects in comparison to a reference light source, e.g. a daylight spectrum.
The colour rendering index is measured on a scale from 0 to 100. A value of 100 means that the light source reproduces the colours of objects perfectly. A value of 0 means that the light source does not reproduce the colours of the objects at all.
LED lamps usually have a CRI of 80 to 95, which means that they reproduce the colours of objects well. However, LED lamps with a colour rendering index of 100 have recently been introduced by manufacturers such as YUJILEDS and are particularly suitable for use in areas where the quality of colour rendering is important, e.g. in photo studios or museums.
In the printing industry, D50 standard light is the common standard light in Europe. Whether you need D50 standardised light depends on your requirements. If the colours of objects and prints need to be reproduced very accurately, D50 standard light is the best choice.
However, if the requirements for colour rendering quality are not so high, an LED with a high CRI can simply be used. LED lamps with a high colour rendering index are generally cheaper than D50 lamps and easier to find.
At Proof GmbH, we have standard light booths from Just with D50 standard light, but we often only use an LED with 500 Kelvin and the highest possible CRI of 90+ on the winders. Nevertheless, significant colour differences and metamerism effects often occur here when proofs are only viewed on the cutting table. We therefore always use the standard light booths for a comprehensive colour assessment.
Unfortunately, no retrofit solutions are currently available for simply replacing ‘old’ D50 standard light neon tubes with LED tubes, for example. As neon tubes will be banned from 2024, completely new LED units must currently be purchased and installed from Just, for example, when replacing old D50 standard light neon tubes. However, at several thousand euros, the replacement is currently still quite expensive.
More articles related to this topic:
Colour deviations in 2023 PANTONE Color Bridge Guides
After Eddy Hagen pointed out in this posts, that there were some major colour deviations between the brand new PANTONE Solid Coated Guide 2023 and the previous version especially for the PANTONE 2635 C, I was curious to lookup the same colours in the new PANTONE Color Bridge Coated Guide of 2023 and compare the colours with the previous version. I measured a dE00 of 8,15 between the two colours that Eddy mentioned, which is really far apart from how accurate PANTONE colours should match between the different PANTONE guides. … read more
New iPhone colour measuring devices: xade nano+ in test
A new generation of colour measuring devices is entering the market: in contrast to the classic measuring devices, which are available as a fully encapsulated system either as a colourimeter or as a spectrophotometer, and then supply the data to a computer via an interface or app or display it directly, the new generation of colour measuring devices consist only of lighting and software, with the optics of a modern iPhone from Apple being used as the sensor. Until now, there have been two categories of measuring devices on the … read more
Proofs with Digimarc EAN codes and verification
Digimarc is a digital watermark that can be used to embed information in images, videos or other media. Digimarc watermarks are invisible to the human eye, but remain recognisable to special software or devices. Digimarc is becoming increasingly popular in the packaging sector in particular, as this technology allows the digits of the EAN barcode and more to be applied invisibly to all areas of the packaging. Digimarc and EAN barcode at the supermarket checkout When scanning at the checkout, the checkout staff do not have to search for the … read more
Proof.de is featured twice in the “Fogra Aktuell” magazine
In the current issue of Fogra News “Fogra Aktuell” Proof GmbH is involved in two places. Firstly, a summary of the Fogra report on our first FOGRA55 certification for seven-colour printing with extended colour space in CMYKOGV appeared. You can also find more information on our FOGRA55 certification on the Fogra website: https://fogra.org/en/press-releases/fogracert-erste-cpc-zertifizierung-fuer-fogra55-cmykogv-330 and on proofing.de: And secondly, there was a report on the completion of the research project for textile digital printing, FOGRA58, in which we were allowed to investigate and test the proof capability of the new textile … read more
“Digital First” often means “Colour Problems Second!”
Whether it’s a large global corporation or a small company, the following often applies to designs or redesigns today: we develop everything for digital first.
We passed the first proof certification for the 7C proof under FOGRA55
A few days ago Proof GmbH was the first company to be certified for proofing for the new 7C exchange colour space FOGRA55. Fogra has developed characterisation data for extended multicolour printing with the printing colours CMYKOGV – i.e. cyan, magenta, yellow, black (contrast), orange, green and violet – FOGRA55 as part of a research project over the past few years. The characterisation data and the ICC profile Ref-ECG-CMYKOGV_FOGRA55_TAC300.icc have been published on the Fogra website in recent weeks. We have now carried out the certification via GMG ColorProof, as … read more
Fogra60 proofs for metal decor printing available
From now on you can order proofs for metal decor printing on white sheet metal at proof.de: The ICC profile for Fogra60 is Metal-Printing_MPC1_FOGRA60.icc
RGB colour spaces explained
RGB colour spaces are colour systems that represent different hues with the three primary colours red, green and blue. RGB colour spaces are used in digital image processing, photography and computer technology to precisely define colours. The most important RGB colour spaces and their special features are: sRGB sRGB is the most widely used RGB colour space and is used by most monitors, printers and digital cameras. It was developed by HP and Microsoft in the 1990s to create a standard for colour representation on the internet and on various … read more
New feature: Orders & individual items can now be reordered with a single click
From now on, it’s much easier and faster: in the Proof Shop, you can call up and reorder entire orders or individual proofs directly from your order history. This saves you from having to re-enter every detail and gives you the assurance that all settings will be exactly the same as last time. With just a few clicks, your proofs are reordered – reliably, easily and in no time at all. What exactly is new? You can find your order history in your customer account. There are two new options … read more
New certified proof papers at proof.de
In recent years, various problems have arisen with our previous proof paper supplier. On the one hand, we sometimes had to wait more than three months for paper deliveries; on the other hand, we sometimes had significant problems with batch-to-batch discrepancies, surface defects and much more. After lengthy deliberations, we decided in December to replace all the paper. We therefore received pallets of new paper at the turn of the year, which we are now gradually incorporating into our production. There will be no hard cut, but the new papers … read more