GregorieL
Below is something that I put together that I provide printers that are considering another competitors ink:
Process Ink Testing Considerations
There are many reasons a printer may choose to test a competitors product, may it be pricing, curiosity, or just to have an approved back up supplier. There are several factors that should not be over looked when testing and/or making a change to a new ink. Thoroughly evaluating a product will insure that additional manufacturing costs are not incurred by a lesser product. Most importantly, keep in mind, when the price is the deciding factor, there is a Unit Cost i.e. (Price per pound) and there is a Cost to Use which directly affects manufacturing. The cost to use, if the product doesn't out perform your current product during the evaluation, can far out weigh the price per pound savings.
Below are important factors that should be taken into consideration prior to making any change from your current products:
Service / Availability
Is the ink supplier the manufacturer or a distributer? When dealing with a manufacturer you are dealing directly with the source. Should you have a special need / request the manufacturer can readily fill your needs. Where as a distributer is a middle man; to whom which represent various manufacturers products. Occasionally, distributers will drop one brand for another forcing the printer to re qualify another ink from the distributer and/or find another source for the product they have been using.
Does the vendor have the resources to provide immediate technical service, should the need arise? Readily available technical service, when required, can considerably reduce down time. Any down time incurred results in lost profits. When dealing with a local manufacturer technical service is readily available. Therefore, should the need arise, a manufacturer will have the resources to make the necessary product adjustments to suit the application.
Is the product stocked locally and/or can you get it the next day when required? More often then not, printers keep a minimal inventory on hand to reduce waste and keep payables to a minimum. It is not uncommon for a large job to come in that needs to be printed ASAP in order to meet a delivery deadline. If the ink distributer is unable to fill an order by the next business day, this can result in lost revenue due to lack of material required to produce the job.
Product Testing / Performance
In a perfect world, the proper way to evaluate a new ink, versus the current product being used, is to put on a test form using un calibrated plates (linear). However, most ink evaluations are done on live jobs. Therefore, it is best that both inks be run on the same job in order to see what takes place when the products are swapped out.
When the new ink is put into the press, it should be run to density only, rather then visually matching the proof or the previously printed O.K. sheet, unless the plates being used are linear. The reason behind printing to density, most printing plates have a curve applied in order for the press to match the proof using the current set of inks. If the new set of inks are put in the press and run up/down to visually match, there is a good chance that either too much or too little ink film will be used to achieve color.
When an ink has too much dot gain the density will have to be reduced to compensate. In most cases this optical dot gain is mistaken for a stronger ink. By reducing the density, to reduce the dot gain, in order to visually match, you are also reducing the saturation and the color gamut that can be reproduced. Furthermore, a lower ink film will be more difficult to control especially on light coverage jobs.
If the ink is lacking dot gain, appears that more ink needs to be run, to match the proof, the density will have to be increased. Not only does increasing the density waste ink it also causes the operator to run more water in order to keep the print clean. Additionally, a heavier ink film requires more time to dry.
Plate curve corrections can be made to correct dot gain deficiencies should they be required after a brief initial test is performed, after running the inks to density only. The following should be observed and documented when performing the test versus the current inks:
• How many sheets it takes to get to density?
• How did the ink respond to the operators input?
• Did the ink densities remain stable during stops and starts while making ready? If not, how many sheets did it take to come back to density?
• Did the ink keys, duct speed, and/or water have to be increased or decreased to achieve density? This is critical as it will tell you how well the ink transfers, resulting in additional or reduced mileage.
• How long does the ink take to be dry enough to put back through the press?
• How long until the job is dry enough to put through the bindery?
All of the above directly affect manufacturing costs i.e. (Cost to Use). Should the initial testing pass, after evaluating the above, it is in the printers best interest to run an extended trial for no less then 7-days. This will allow the printer to see how the product performs over a variety of jobs, press conditions, and to get a better idea of any real cost savings versus their current product. Only at this time should the printer make the decision to change products.
I hope you find this useful. Also, not that it really matters, I am not a salesman for an ink company, my background is technical.
Regards,
Bob
