Dot Gain Fibrillation and Moiré.

In the wet on wet printing environment some unique problems can arise.

When you print with Half tone dots, dot gain can be a constant source of trouble.

The dot may be a small circle on the positive, but after several squeegee passes it turns into a much larger dot.

This increase in size is called dot gain and can cause an image to look 30% darker than was intended.

AM separations or half tones rely on the space between each dot to maintain a color value.

When ink unintentionally squeezes into these spaces the trouble begins.

A quick cleaning of the screens will fix the problem momentarily, however a short way through the run, dot gain will reappear.

Most half tone separations look best at the beginning of production and then look progressively worse as dot gain and ink build up change the image.

The mid point of the gradient moves outward towards the paler edge destroying the integrity of the shading.

All screen mesh has a fixed resolution.

This means that as dots get smaller, eventually they get so small that they fail to wash out on the emulsion layer.

The smaller dots often become plugged up with pigment, creating a chopped off look in the gradations.

Halftone dots traditionally "stack" one on top of another.

This works great for flat dry surfaces but with wet on wet printing it is similar to putting on snow shoes and jumping on a trampoline covered with Neapolitan ice cream.

Dot stacking is one of the biggest drawbacks of simulated process and 4 color process.

The stacking of the dots creates not only blurry resolution but can also cause color contamination.

This is where yellow dots are being printed over red dots and the pounding of the squeegee eventually causes the red dots to mix up through the yellow layer and through the mesh of the yellow screen turning the ink into an orange mess.

This means cleaning and replacing the yellow ink during a production run.

HALF TONE STACKING LEADS TO SERIOUS INK CONTAMINATION PROBLEMS.

Index separations print thousands of tiny squares butt to but.

This means a single softer layer of ink that is much easier to control especially during long runs.

There is no space between the squares.

Each one is completely surrounded by ink.

The little "bumps" created by half tones feel like sand paper by comparison.

This means that you are no longer fighting a war against the natural elements of wet on wet printing.

Each square of ink is held in place by those surrounding it.

Half tones allow fibers to stick up between the spaces.

Severe fibrillation can have your customer demanding their money back.

Durability is of utmost importance with any printed garment, after all they are made to be washed.

Think of the square dots as a large tiled floor laid down over carpet.

100% of the image area is printed giving intense saturation of colors and superior washability.

These butt to butt squares are ideal for printing rough substrates like canvas, burlap and towels.

The single layer of ink is not only softer, it also traps the fibers of the shirt and greatly reduces fibrillation.

Fibrillation is a problem with standard halftones because the fibers of the weave stick up through the spaces between the dots and make the print look faded after just a few washings.

Our users report consistent prints over 10 thousand units with no ink contamination or the need to clean the screens.

This has a great effect on efficiency and profits.

Using a special print order, each color is laid down beside the other.

This ensures that dot gain is controlled and actually uses the wet on wet to mix the edges of each square creating superior gradients to any other method.

If you look closely at a good index print you will not see any dots.

The wet on wet action and the squeegee hits subtly blend them together.

Detail is maintained because there is no need to have a space between square dots and many thousands more of them can therefore be fit into every square inch.

There is no direct comparison between pixels per inch (PPI) and dpi but the printed shirt looks to have the resolution of an 85 to 90 line screen

It is a scientific fact that FM supports higher resolutions.

This is not an opinion - it is a well proven fact - believe it.

IF YOU ARE STILL NOT CONVINCED FOLLOW THE LINK BELLOW.

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Click this button to see the difference between printed half tones and FM squaredots.  

The white square represents the space left for the next color in the wet red ink.

The next color reclaims the area overrun by the dot gain of the red ink and in turn begins to mix to an intermediate shade.

The animation below illustrates this mixing and dot gain controlling action.

Thousands of tiny square dots about one 200th of an inch across are printed in a grid to recreate an image with both bold color and sharp resolution.

The square above represents an area .05 of a square inch - that is about three dots per thread.

The wet on wet process is no longer your enemy - it becomes an ally in a particularly difficult process.

Each square dot lands on an empty space provided for it.

This ensures that ink only lands on fabric and is absorbed into the garment where it was intended to go.

Buildup occurs because ink is pushed through the mesh and does not leave with the shirt.

Index separations outperform all others in the automated production environment for clarity and consistency.

Squaredot separations are superior to half tones for manual presses because they are not as sensitive to variations in squeegee pressure.

Whether you are using a push or pull stroke it is very difficult to maintain equal squeegee pressure on every stroke.

Any manual printer who has ever put too much pressure on a halftone separation has witnessed just how easy it is to create a dot gain mess.

With square dots you would have to really over do it to cause the same kind of problems.

This means less cleaning of screens and more production time.

After all we only get paid to print shirts - not clean screens.

OLÉ NO MOIRÉ

The size of the square dots can be made larger or smaller to suit any size mesh.

The random pattern of the dots means that Moiré problems are a thing of the past.

There are no screen angles or LPI settings to fuss over

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All of the square dots are relatively large compared to the variety of dot sizes in a traditional half tone.

Since they are all equal size and well within the latitude of the screen mesh and emulsion's ability to render them, it basically means that all of the square dots will wash out cleanly and sharply.

Halftone dots are infamous for creating those unwanted linear patterns called Moiré.

How many times a year do you re-burn screens because of moiré interference ?

This waste of time and emulsion can cost thousands of dollars a year.

 Moiré patterns are especially devastating to gradations.

The Moiré patterns can be caused by interference from the screen mesh or formed when printing over the fine ridges in the fabric. The small dots will often not wash out or fill in creating clipped gradients with nasty saw tooth edges.

Halftone blends between two colors will commonly suffer serious banding problems (left)

while smooth seamless blends free of banding (right) are the norm with Screenprint Separator.

The software is particularly handy when you are supplied

with a design drawn in hundreds of process blends.

Instead of having to redraw each one for hours on end, the graphic needs simply to be rasterized in Photoshop and turned into spot color with Screenprint Separator.

Copyright Screenprint Separator 2003