The "Frank Lee" Blog...

Hello. I’m Frank Lee. I am a fictitious character that deals in facts! Just like the old television series "Father Knows Best" – Frank Lee is your mentor that delivers to you the wisdom to succeed in the screen print business. My motto is "time is money, so don’t waste either".

There are reasons why folks have come back time and time again to Freehand Graphics – results and success are those reasons.

I am on your side and understand that we wish we could buy the best of the best for each process and that you will not always be able to do so but there are a few core items that are critical to the process of success so evaluate your machines and needs and put resources toward things that will increase your efficiency and lead to business success. We are all in the business of printing so have the right tools.

I have decades of printing and pre-press experience that I will share with you. Frankly spoken and very direct with a fatherly intent to improve your business and enjoyment of the industrial method of Screen Printing.

Some folks like the long technical explanations and others just want it boiled down to an advisory level. I will do just that and add a few thoughts of common sense and history. In the end, advice is great to have but results are what matters.

30 years ago, my screen-printing (we called it silk screening) beginnings involved hand "C" clamps on a work bench to hold the frames and an exposure unit made of portable fluorescent lights. Frames were held down by weights, a metal plate and foam. A big day was when we nailed a 2" x 4" piece of lumber to the table and upgraded to two color work. So I understand humble beginnings and low budgets. What I learned was that as I made money I invested properly into items that made me a professional printer and the proper use of those tools made me a success. In a short time the business grew into a multiple automatic business with three production locations producing many prints. This success can also be yours if you treat yourself and the business professionally. Not enough Screen Printers get proper guidance so I am here to share what I know. Take this information and apply it daily and you will have the success at any level you desire enjoying the industry as I do.

First it’s important to understand the technology and supplies to fully understand how and why things happen.

Your RIP software has a lot less to do with the density than most users understand. Yes, it’s where we control the settings for the printer such as resolution and ink flow, but it’s the physical link between the film and ink that does the most to achieve proper density.

Films:

There are many styles of film even from one company. Each has different properties and a different abilities. You get what you pay for. It cost more money to make a better film and the result is better too. Always choose the best film possible, the film is what makes your screen and you are a "screen" printer. If your screens are second rate then so are your prints. There is just no other way to put it.

The emulsion layer on the film certainly helps speed the drying process and edge quality greatly reducing dot gain as well. Avoid using a films with a thin, almost "clear" appearance and never use a "non water proof" film. Your dye ink is water based so use a proper film. The name alone "non waterproof" should tip you off that its not the best product for your needs. The slightly cloudy emulsion of the film does not effect the exposure process.

Inks:

There are two styles, Dye and Pigment. Both make films and both need to be matched to a proper film supply (there is that focus on film again). Pigment and Dye are radically different inks so don’t choose the wrong film. Some claim there are films that work "great" for both, wrong, a film works "great" for the ink it was designed for and maybe it works "ok" with the other. By the proper film for your inks and "test" them before you buy bulk.

The industry standard is Dye ink:

Dye ink is available by many suppliers and works with lower cost films, which does not mean lesser quality films. Dye ink requires a thinner emulsion layer than pigment ink and the thicker emulsion layer is where to cost of manufacturing and purchasing film rises.

Air dry technology:

Using dye ink means that you are dealing with an "air dry" technology. One of the reasons we like inkjets is that there is no "heat" involved in the process like with a laser printer so registration is more consistent. The films are not shrinking due to intense heat. However that also means the ink is not "fusing" as fast. It takes time for the ink to fully "cure" not just dry.

Using screen print terms, you know what happens if you print a shirt and just "dry" the ink rather then properly "cure" the ink. Well, it’s the exact same thing with inkjet films.

Dye ink is aqueous meaning it’s water based with dye and uv blocking agents to make up the density (UV blocking) to block UV light in the exposure unit. Giving the film more time to cure before use means more water will evaporate leaving behind only the dye and UV agent. When the water is fully evaporated we call that "cured". A cured film is not only greater in density, but it’s much more durable, scratch resistant and archival.

Dry ink is like pudding, it may be dry to the touch (on top), but below the surface it’s unstable and easily reactivated by moisture. Press a "dry" film up against a damp emulsion screen (not fully cured) then turning on a hot exposure lamp creates a greenhouse effect. Your film will likely fall apart after its first use.

Plan ahead:

Films measured soon after printing will always have a lower density reading that those allowed to fully cure. A few hours is good, over night is best.

Yes, it is possible to run a screen print shop and make your films a day in advance. Yes, it involves getting other parts of the prepress process more efficient but it certainly can be done and by doing so you will always have the best films you can make. Better films make better screens and prints improving your business quality. Strive to be the best you can be. Do things right as often as possible.

Now that you know the facts you can better deal with results good and bad. At least you’ll know how and why it happens.

We are screen-printers so screens are the most important part of the process. A poorly made screen means bad printing and "production down-time". Remember my motto "time is money". Screen-printers buy everything they say they need, but many do not own a proper screen drying cabinet, making their own devices which frankly speaking are "junk", creating more trouble than they are worth.

Here it is, when dying a screen you must dry the screen with the "print side" facing the floor and the "squeegee side" facing the ceiling. Exactly as it is when you print with it.

Reason: Gravity forces the emulsion to the proper side (print side) leaving the heaviest layer on the proper side of the mesh. This improves screen making, reduces exposure time, increases the stencil well which leads to better ink coverage and a lot more.

Stop making this early mistake. Get a proper screen drying cabinet or modify your setup to allow screens to be dried in the proper position.

Fact: the mesh layer between the emulsion layers slows down light waves and restricts their ability to expose emulsion so an improperly dried screen that has the heaviest emulsion layer on the wrong side (squeegee side) will not capture detail or wash out properly. The first sign of this problem is the need to increase exposure time and the loss of fine detail; not to mention under-exposed (slimy) emulsion that washes down the drain. Sound familiar?

Many questions are asked about the method and amount of passes when applying emulsion. Frankly, do what you need to do to get an even smooth coating making sure your last "cleaning" pass is made on the "squeegee side" forcing the heavier coating to the "print side" as discussed previously under "Screen Drying".

Fact: Capillary emulsion films are applied to the "print side" of a screen because that is the proper side to have the heaviest layer of emulsion on for reasons of proper exposure and printing. You need to achieve the same result using direct emulsions.

Humidity is not a good thing. The idea is to remove water from the process not to introduce more. If it has never been explained before then let me tell you, most "de-humidifiers" don’t work, in fact, most introduce "more" humidity than they remove.

The small de-humidifiers that you buy at the local appliance store have such small fan motors that are over worked and they heat up. That heat causes the coil on the back of the unit to sweat. That sweat drips into the pan that you empty every day. Put your hand to the unit and tell me if you feel warm or cool air blowing out the back?

Seriously, do you think there is that much water in the air? If so we’d be fish and not printers.

Frankly speaking, you get what you pay for. Large capable industrial disaster recovery style de-humidifiers work well. These units run cool to the touch meaning that the water they collect "is from the air". Many have their own internal pumps as well. Costing only a few hundred dollars more than the units that don’t work well this is a good way to not only spend your money wisely but to get the proper job done.

I personally use an Oasis brand de-humidifier capable of pulling 6 gallons of atmospheric moister in a 24 hour period of time. Used mainly for flood recovery, it is ideal for keeping the screen making room "dry"!

If I collect 3 gallons of water from June to September that is a lot and it gets humid around here in July and August.