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ACC-0009 • Achieving Density without a Densitometer

Achieving Film density does not have to be a "shot in the dark" for users without densitometers. AccuRIP Software delivers real world solutions - your world!.


To start let’s address a destructive rumor -the rumor being that you can use the standard Epson printer driver to make great film positives. It doesn’t. If it did, Epson would not represent a number of RIP solutions including AccuRIP. It lacks ink lay down control among other needed and valuable controls.  Freehand was contracted by Epson to develop AccuRIP Black Pearl SE for Epson’s screen print bundle for two printer models. Think about that the next time you are given misleading (well meaning) advice about the software products you need (or don’t need) to successfully control and run the graphics side of your print business. There are technical computer and postscript language functions beyond the capability of a standard print driver. A RIP manages postscript of all graphics files, as well as allowing for the cleanest spot color and halftones separations, AND they offer much greater ink control which is the key to film making success.


Want a daily dependable “standard” that you can count on? Of course you do, this is the key to a successful production business, any production business. Until you have solid working standards you can not and will not achieve production success. Each day will be an adventure, likely a bad one. Let’s get this right.


Before you can dial in every step, product, and procedures regarding screen making (emulsion coating techniques, mesh color and counts, tension, exposure time and pressure, wash out techniques…) you must absolutely, positively, have a properly dense film. Without a properly dense film everything falls apart. You will not develop reliable working standards. How can you determine proper exposure settings if the film is not properly blocking UV light?


Ok, lets talk about the “real world”, Freehand helps thousands of NEW users each year setup shops as well as streamline established shops. Running into a user that has a film reading densitometer is very rare. People just don’t invest their money into such a device or know that such a device exists.


A transmission densitometer reads the levels of UV light that pass through the inked areas on film. Those that use one have confidence in the films they produce, thus they know how to dial in their pre-press products and systems, as well as identify weaknesses to overcome.


In the real world, people hold film up to their eye to see if the film is “dense”. If it looks black they feel it is ok to use for screen making. As common as this is, it’s a useless method. The goal of film is to block the UV light emitted by the exposure unit, protecting the emulsion that is UV light sensitive. Density alone has less to do with success than the actual blocking of UV light waves. The reason the human eye test method is flawed is because humans can not see UV light waves, they are invisible to our eyes. Take for example the once popular industry supply called Rubylith by Ulano. This red masking film has been used to make screen for decades. You can see right through it just like a pair of UV protective sunglasses, yet it blocks UV light just like sunglasses. As you can “see” it’s not about density you can visually measure, its about the ability to block UV light waves up to 420 nm (nano meters). Most screen emulsions react when exposed to UV light between 320 and 420 UV nm.


So how is a screen printer supposed to know good from bad?


Freehand Graphics recognized and solved this problem over a decade ago. AccuRIP is the only RIP that addresses this need internally (part of the software functionality). By removing the need for an expensive densitometer, Freehand delivered an even more efficient system for all users. Quick and easy, all a user needs to do is print from AccuRIP the Droplet Weight Density Test print page at the printer resolution they desire.


With all 15 ink droplet density settings represented, at different ink coverage settings (with standard being the default), that is a total of 45 different possibilities when producing film. The film is printed with easy instructions how to properly and fully benefit from the test film. All you have to do is expose the test film and wash it out using a gentile spray. The first number to washes out easily is the number for your shop and supplies. The lower numbers also use less ink so it’s a great test to insure you are not over driving inks, which cost more money and produce less sharp films.


So what does this all mean? It means, you will quickly discover the best AccuRIP settings for ALL your pre-press screen making supplies and systems. The test does not just show you what is best for the RIP, it shows you what is best based on your given combination of equipment, supplies and systems, not on some general specification on a website from tests performed in a laboratory. AccuRIP delivers real world answers - your world. This is why AccuRIP is the industries leading RIP software. Our success comes directly from the success we bring to others.


Not just software, but practical technology for screen printers by screens printers. Use Freehand products to achieve your best results.

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