On April 17th and 18th I had the pleasure of participating in a press trial with MacDermid Printing Solutions to evaluate the effectiveness of their new Stabil-X offset printing blanket. I am writing today about the TVI curve of the various trial conditions.
We ran five different conditions during the course of the trial. All the trials shown in the graph involved only one printing unit running magenta ink. The curves also represent the averaging of 10 press sheets. The five trial names and descriptions are:
- STX opt - Stabil-X blanket run at optimum packing level
- Press std - The set-up of the press when we arrived
- STX -.003 - Stabil-X purposely under packed by 3 thousandths
- STX +.002 - Stabil-X run at 2 thousandths over
- STX +.004 Stabil-X run at 4 thousandths over
As one might expect the STX -.003 has not only the lowest TVI, but also a very poorly formed curve. A pretty good example of why you do not want to run your press under packed.
The Press std curve shows how this shop runs the press on a regular basis. Notice the hump in the TVI curve from 25 to 50%. Not an uncommon condition on many presses.
The STX opt curve is much smoother than the Press std curve, missing the hump from 25 to 50%. Also, run at virtually the same densities the dot gain (50%) and overall TVI is lower at all points than the normal press set-up.
Even the two STX over pack conditions produced smoother overall TVI curves than the press standard set-up. While the TVI is higher in most cases this is to be expected when adding that much squeeze to a blanket that really does not need it.
I will continue to write about this press trial for a least 2-3 more weeks. There is a great deal of data and information to still go over. I even have some sheets here I will be doing additional readings on.
If you would like more information about the MacDermid Stabil-X blanket, please contact me and I will put you in touch with the right people at MacDermid.
Over the coming weeks I will be writing a great deal about my last two days in Chicago. Kevin Kocher of MacDermid Printing Solutions (offset blanket manufacturer) invited me to a press trial of their new Stabil-X blanket. So, right about now if I was one of my readers I would be thinking how exciting can an off-set blanket be? In a word this blanket is cool. It truly is the first revolutionary technology change in blankets in decades. In short this blanket is a patented combination of a polymer backing (instead of fabric) with Kevlar fibers running through it as well as synthetic fibers to replace the nitrile rubber and cotton.
We took a great deal of measurements during this trial, and while I have not had time to fully review the data I can tell you that this blanket printed better. Better being lower dot gain at the same density levels as conventional blankets, a smoother shaped TVI curve than traditional blankets, and most importantly less density and dot gain variation in sequential pulls.
Over the coming weeks I will be including both numeric and graphical results of this test, showing how we utilized ColorMetrix to confirm the visual results with objective factual data.
I am often asked by customers one of two questions; 1. Which instrument that I already own should I use with my Colormetrix product; 2. Which instrument should I purchase to use with my ColorMetrix product? While my good friends who work for brand X and brand G will tell you the answer is simple (one of the ones they sell of course!) I find it to be one of the most difficult questions to answer.
The answer to this question begins with one word; application. Your application of the instrument implies several more questions:
What will be measured? - When I ask this question I am trying to determine if a scanning instrument like an EyeOne or PULSE can be used. Or it a hand-held instrument like a 528 or SpectroEye will be more appropriate. If press sheets with small color bars are what will be measured, a scanning instrument (of the type mentioned above) will not be appropriate. If, however, proofs with a large control strip (which we can set-up to be scanned by the EyeOne or PULSE) will be measured, then the speed of input and decreased opportunity for measuring the wrong patch makes the scanners more appropriate.
What is the spectral response of the colorants & instrument? - This one gets a bit technical, but is important. I visited with a customer last week who was testing out a new instrument. He is concerned that he will not be able to use this instrument to measure his proofs for color management purposes. This is because some spectrophotometers are built with spectral response every 20 nanometers while others respond every 10 nanometers. In the case of this customer’s application, the yellow ink he is using has a sharp fall off in the spectral response curve between two of the 20 nanometer points being measured by the instrument in question. Please do not read this section to mean that 20 nanometer spectrophotometers are bad and 10 nanometer instruments are good. It is a matter of application. There are many other factors that determine the overall quality of an instrument. In the case I just sited, however, this was an overriding factor.
Will you use the instrument stand-alone? - If this instrument will always be plugged into a computer running a ColorMetrix product in general a less expensive instrument can be purchased. If on the other hand, the same instrument will be connected to ColorMetrix, and stand-alone, then you will need an instrument with a display and battery operation. Just think of the price difference between a PULSE and a 528 or an EyeOne and a SpectroEye. That difference will pay for the ColorMetrix software and a computer to run it on.
Who else will be measuring the same samples? - If your customer or someone else in the production cycle will be measuring the same samples and expecting the same results you will both need to use the same instrument. It would be even more helpful if you also looked at Gretagmacbeth’s new netprofiler product. This allows two instruments to measure virtually the same (or so the manufacturer claims - I have not yet had the opportunity to test this exciting product).
There are many more questions that one could ask, but hopefully those listed above will get you going in the right direction. Always feel free to give me a call or send me and e-mail and I would be happy to assist with the process.