ARE THERE ANY TECH­NI­CAL/PRAC­TI­CAL/COST LIM­I­TA­TIONS BE­HIND SCI­EN­TIFIC METHOD OF COLOUR SHADE MATCH­ING OF FAB­RIC?

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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

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