Fundamentals of Proper Color Matching

When considering the issue of color matching, there are a number of topics that could be addressed to help improve efficiency. Some topics take longer than others to learn, while others are very simple to grasp and easy to implement if only we take the time to do the process correctly. A large amount of time is consumed in color matching, so whatever can be done to make this time more productive, the better off you are. This article will share four fundamentals of color matching. If you do not practice these fundamentals, try them for a few months and you will see the benefit. If you are already doing these things, use this article to refresh your memory and rekindle your commitment to this process.

The first fundamental in color matching is to weigh everything. It is a common practice to slightly "tweak" a color or add thinner or some other additive without weighing it. This makes it virtually impossible to reproduce the exact color at a later time. The use of an accurate scale that is regularly checked for proper calibration is imperative. A general rule of thumb is to use a scale that weighs at least .1% of your total batch size. For instance, if you are weighing a batch that is 1,000 grams, your scale should weigh down to one full gram. If you are only weighing up 100 grams, it is essential to have a scale that will weigh one tenth of a gram. The only way to perfectly reproduce a color time after time is to know the precise weights used for the original match.

The second fundamental in color matching is to document everything. Every time you add a component to a color match you should document it immediately. This discipline will prevent the confusion that sometimes occurs when you get side-tracked. Properly documented color match data is critical in reproducing the color at a later date.

Fundamental three is probably the one that gets the least attention, but is just as critical as the others. Fundamental three is: re-weigh every match. When most technicians begin a color match, they weigh-up an estimate of what that specific color formula will be. They will make a print, and then add something to adjust the color. This procedure may take several attempts before the desired color is precisely matched. If this process takes place using only the original estimated weigh-up, their final formula may still be slightly off. Even in a color match lab environment, each time you flood and make a print, you lose approximately three to seven grams of ink, even if you're careful. That is why you should never make more than two adds to a specific ink sample. After that, re-weigh the formula you have up to that point and correct it. The last step to actually match a color is to re-weigh a sample of the finished formula. This will insure that your finished formula is correct.

The last fundamental of proper color matching is to accurately file each color match. This does not mean to just write down the formula on a loose piece of paper. It is generally suggested to use a 3x5 or 5x7 card file or a computer database system to record all of your finished color matches. On this card or computer database system there is much more information that needs to be recorded besides the formula itself. This card should contain: the date matched, screen mesh, screen tension, squeegee durometer, any thinner or additive that was added, substrate matched on, DE if a color computer was used, what light source the match was done under, work order or job reference number, customer reference, emulsion build, any press-specific adjustments and a small color chip of the final match.
This information is critical if the need arises to repeat a color match.

Practicing these four color match fundamentals will guarantee consistent color matching:
1. weigh everything;
2. write everything down;
3. re-weigh every match; and,
4. accurately file each color match.