ARE THERE ANY TECHNICAL/PRACTICAL/COST LIMITATIONS BEHIND SCIENTIFIC METHOD OF COLOUR SHADE MATCHING OF FABRIC?
Colour shade matching of fabric by human eye has been traditionally done for decades which is subjective and non-repetitive. Although the scientific way of shade matching is available commercially (e.g. based on delta value), the industry rarely uses it. Why? Are there any technical/practical/cost limitations behind this? Or is this because of lack of approval from the buyers?
Some companies may have designs on textiles that would require the consideration of human variable to reduce waste. For example, even when we use the spectrophotometer, a colour within a tolerance can still be ‘looking’ off colour (metamer ratio considering colour saturation). A human element can look at this issue and decide if the new dye lot can still be on the sales floor, next to an old dye lot, especially for basics. The human element can also work with various teams to ensure that if a dye lot problem is present, then they can direct those goods to another country, or a separate state to selloff-price, etc. They will also consider how the colour looks with dye to match trims or the lighting of the environment. This can help a company reduce waste issues, and as a result will allow more sustainability.
Some companies may require a spectrophotometer report as well as a visual report. This is used as QC protection for both the manufacturer and the vendor. Personally, I like this because even if you have a colour team, they may not be with a company for years, so having logs can also help the dye manufacturer.
Overall having done the work of a colour specialist, the human element works with technology such as X-rite vision tests, Spectrophotometry, Macbeth Light Booths, etc. Although the human element is affected with problem solving issues like colour, saving money etc., they also protect the customer experience by perceiving colour the way a customer does such as what can pass on a floor without too much metamerism. The intuitive human visual experience is a hard thing for tech to replicate.
I am not sure how colour consistency will be impacted if a company just exists in an on-line capacity. Mainly because it won't be on a shopping floor with other dye lots. I am sure this would depend on the brand QC.
KATHERINE SCHILDMEYER FOUNDER, KS APPAREL DESIGN & CONSULTING, USA
The industry is preferring human eye over scientific methods because of the reason that human eye has been fulfilling this purpose appropriately since ages and before any technology could make its ground, humans used to match the colour shade with naked eye only. Now in spite of some scientific methods being available, their rare use can be majorly due to two reasons: firstly, not everyone is aware of these methods; and secondly, even if someone knows about such methods, he/she has not seen anyone else using automatic machines for this colour shade matching process, so they feel uncertain about the results. The cost of machine also matters. If someone makes up his/her mind to invest in such machines, the price seems high to them and it is quite difficult to find operators in the market to perform this operation.
Another way of looking at it is that the human eye can realise shading of cross and plaid fabric better than scientific methods. But as per my observation, automation machines can do the job better in case of solid fabric.
LONG VU MATERIAL SALES MANAGER, YOUNGONE CORPORATION, VIETNAM
Colour, shade and colour tone judgements are very subjective. Frankly speaking, it all depends on QC inspectors and merchandisers as to how they follow standards and till what limit. The most accurate and scientific way is by using the Delta colour or any other similar function. But, at the end of the day, the buyer's decision counts and it is up to the buyer what he/she wants. I think it’s not the issue of cost or affordability as the manufacturer has to invest in technology if that is a compliance. Most of the dye houses own this technology equipment for colour shade matching process and, according to me, colour shade judgement by
scientific method is still being used by many big and reputed manufacturers, branded companies and labels. Their shade matching process is based on delta E value and the one who expect greater quality in shade matching process works on or less than 0.6 delta Evalue.
Moreover, I want to add that somehow it is true that shade matching is not perfect, especially for very dark shade of colours such as black or olive. But, if it is within the same quadrant, the colour judgement by the scientific method or by a human eye will not vary much.
JEFFEREY GOAY ADMIN AND COMMERCIAL DIRECTOR, GTP GROUP, VIETNAM
The technology of the computer colour matching system ( CCMS) is scientific and objective. The CCMS comprises of a spectrophotometer, a personal computer, and a colour matching software. Spectrophotometers are colorimeters for capturing and evaluating colours. As part of a program to control and ensure colour quality, they can be used by brand owners and colour specification and communication designers and manufacturers to monitor colour accuracy throughout production. Spectrophotometers can ensure colour consistency from the first creative idea to delivery. The spectral reflectance curve for the colour measured with a spectrophotometer is called the ‘fingerprint’ of a colour. To measure the colour of an object generally reflectance spectrophotometer is used.
All QA applications involve comparing batches against a standard. QA functions using CCMS involves colour difference assessment for approved standard and a batch, Colour Difference measure in terms of Delta Ereport and finally pass/fail status for batch production. While the manual process is subjective to human error, the computerised process is 100% objective and most importantly repeatable. It’s a common phenomenon that if two shades of colour is shown to the same person in two different instances, he/she may give different judgments; however the computerised system result will be same, that is the beauty of CCMS. It can also be used for assessing whiteness of Optical Brightening Agent ( OBA) treated samples and yellowness for white textile substrates.
I see the non-acceptance of use of technology for colour shade matching as more of a rigid mindset of the buyer rather than a technological limitation. Any new technology will have initial teething operational problems which can be easily solved with mutual readiness to accept the technology. I have seen some small importers using CCMS, whereas large buying offices are still depending on human eye to do the same. This is probably due to the higher number of people in the hierarchy of the organisation being convinced about the technology. I also feel there is lack of awareness of these crucial new technologies at different levels of academic and industry.
I strongly feel that things will change today or tomorrow, but going by tradition of slow adoption of technology by garment manufacturing industry, the large multinational brand and retailers require taking the lead for faster adoption of this technology.
PRABIR JANA PROFESSOR, NIFT, DELHI, INDIA