3D Printing

Screen printing process it’s more complicated and laborious than digital printing. The entire process is made up of several steps that take so long that it would be a shame to delay or even ruin it due to poor preparation of the printing file.

There are probably a million variations on this process, and everyone does it a little differently. This time we will see it from the point of view of a digital printing graphic designer, who from time to time must do screen printing and the mistakes I have made (and boy I have made mistakes).

First thing first

First of all we must understand that the screen printng is divided into two categories: spot color or four color.

Spot color means that each color is separate prints only in that shade. So if you have a three-color design, you would need to create a film for each of those three colors and would be printed one at a time.

Four color process is used to replicate photographs, paintings and any other kind of art with a variety of colors in different shades and gradations. When using four-color process, the image must be separated into cyan, magenta, yellow and black (CMYK).

Vectors vs. Raster Image

Before starting the creative process you must be very clear about the use that will be given to your design; since this will depend on the choice of software that we will use to design our art.

Raster image

Raster graphics images are best used for digitized photographs, scanned artwork or detailed graphics.

When you create your design in a raster based software you are kind of married with the original dimensions.

Always remember to start your documents at the intended print size with a resolution of 300 pixels per inch. If you have drawn the artwork at actual size, then scan it at 300 dpi. If your artwork was created a 50% scale, then you will need to scan the artwork at double the recommended resolution (scan at 600 dpi).

Common raster formats include TIFF, JPEG, GIF, PCX and BMP files.

Vector

There is no limit for sizing vector images. Can be resized indefinitely without sacrificing print quality, blurriness or pixelation that occurs when resizing images created in photographic software.

Common vector formats include AI, EPS, SVG, and sometimes PDF.

Avoid web Images

Using images from the web can be convenient, but keep in mind that most of these images are very small and with low resolution (most of the time they are set to only 72 dpi)

Convert your text to outlines

Always remember to convert your font to outline on all your text, this allows to open the file without requiring the original font file or modify the design.

Choose your color

Using a specific Pantone for each color will help to properly match your design without any color variation.

Porosity of the substrate

The porosity and texture of the materials is something that must be keep in mind. For exapmle some fabric has holes that cannot be printed on, so you should keep your design details to a minimum.

Think on the background color

If you are going to printing on a dark color (or transparency), you will need to add white ink layer under the image to make sure the colors are visible.

ALWAYS save an editable copy

When you finally have finish your design, always be sure to keep an editable copy of your work, just in case you need to do some last minutes adjustments.


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Dos-and-Donts-When-Preparing-Artwork-for-Screen-Printing


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Dos-and-Donts-When-Preparing-Artwork-for-Screen-Printing


Dos-and-Donts-When-Preparing-Artwork-for-Screen-Printing

FLAAR-REPORTS photo archive.


Published in Textile Printing
Friday, 10 July 2020 18:24

Color changing Inks

There are several mechanisms in which color changing of an ink can occur, in this article we cover specifically two, photochromic and thermochromic. The first meaning that a specific light type (wavelength) triggers the ink and changes its color, thermochromic means that color change will occur depending on the temperature it has been designed to activate.


Color-changing-Inks

Photochromic T-shirt on its passive state (left) and activated by UV Light (right) (colourchange.com)


Photochromic inks are invisible under artificial light and will appear visible once exposed to outdoor sunlight or UV / black light. These inks can be applied to papers and boards or to textiles. This type of inks and dyes change their molecular structure from a clear or white color and darken revealing its true color (on exposure to specific types of light of enough intensity, most commonly ultraviolet (UV) light sources, (UV light in the range of 300 to 360 nanometers).


Color-changing-Inks

Photochromic pigment of different colors activated by a concentrated UV-light source (nanomatrixsecure.com)


Photochromic dyes are reversible, when placed into sunlight or a UV-Light source they become activated, in an “excited” state, and depending on the manufacturer it takes from 10 to 20 seconds to allow the photochromic compound to turn into a darker color. In the absence of activating light when the UV light source fades, the effect is reversed and they return to their clear state after 5 minutes or less.


Color-changing-Inks

Photochromics are great on white t-shirts but not limited to be used on it (sfxc.co.uk)


Thermochromic ink or fabrics change color in response to temperature fluctuations, meaning heat will enable it to change color at its designated temperature, color change activation occur at temperatures from -10°C up to +70°C, they usually are reversible, changing either way as the ink warms or cools. There are two primary types of thermochromic coatings: liquid crystals and leuco dyes.


Color-changing-Inks

Thermochromic fabric, color change is activated by body temperature.


Liquid crystals dyes rely on liquid crystals contained in tiny capsules. The liquid crystals are cholesteric, this refers to the arrangement of molecules, which means that its molecules arrange themselves in a very specific helical structure. These structures reflect certain wavelengths of light. As the liquid crystals heat up, the orientation of the helices changes, which causes the helices to reflect a different wavelength of light. To our eyes, the result is a change in color. As the crystals cool down, they reorient themselves into their initial arrangements and the original color returns.

Leuco dye inks, are a darker color when cooler than their temperature activation point, and lighter in color or virtually clear when warmer than their activation point, temperature uses of these inks generally fall into three areas: cold, body temp and hot.


Color-changing-Inks

A black thermochromic ink (with body temp activation) screen printed over and obscuring a litho printed image or words, can become clear and reveal the litho image when it is touched or rubbed. (sfxc.co.uk)


A black thermochromic ink with a higher activation temperature can be screen printed onto a coffee coaster, so that the thermochromic ink becomes clear when heated by a hot mug, revealing the message or branding also printed on the coaster.


Color-changing-Inks

Heat-sensitive vans shoes will change color temporarily when exposed to body heat and return to original color at room temperature (vans.com)


Published in Inkjet Inks

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