Your Guide to Colour Separating for Custom T-Shirt Printing

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Your Guide to Colour Separating for Custom
T-Shirt Printing

• DTG PRINTING
• PRINTING
• SCREEN PRINTING

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• When to use what type of colour separation when
  custom printing t-shirts.
• Printing onto T-shirts via the old school screen
  printing method is not always simple and
  straightforward. The process to make the decision
  involves variables that determine the approach
  you take when it comes to custom printing clothes
  such as t-shirts. So, before you decide what
  process you want to use, you need to know about
  the variables

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• The first variable in the list is the picture
  itself and the way it will get separated before
  it is sent to the screen room. The artwork or
  design you create is made with fundamental
  variable building blocks that are the reason why
  you have to consider how you will screen print
  your design
• Is it a bitmap or a vector file format?
• Is the resolution of your design or artwork good
  enough to start the process with?
• Your artwork will have either one or more than
  one colour. Decide how many colours are too many?
• The object in the design, artwork, or logo may
  contain gradients, tonal changes, or solid spot
  colours. The artwork can have text too. So, the
  size of the artwork is crucial to the process.
  Similarly, the thickness of the key lines, if
  your design has any, is important to be
  considered as well. 
• What colour garments or fabric are you printing
  your artwork on?

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• Many customers, however, will not take into
  consideration that so many factors are required
  when assessing artwork and designs. If they end
  up getting a graphic designer to produce their
  design or artwork who is t-shirt trained, then
  the graphic designer will consider all the
  above-stated factors because of his/her prior
  knowledge and expertise in the field.
• Screen printers are usually given very
  low-resolution and low-quality pictures and
  designs downloaded directly from websites for
  production. These images are, however, not
  sufficient for direct reproduction because web
  graphics are designed to be a size as small of a
  file size as possible. The reason for this is
  that this way, the web page, the images are
  lifted from, has a faster loading speed.
• Suggested Read Digital Printing vs Embroidery
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• Such images are then more than often have to
  re-drawn with the help of a vector program, for
  example, Adobe Illustrator or similar software.
  Or they are exposed to a number of Photoshop
  filters in order to try to enhance them, or
  sometimes both. 
• Assuming your design or artwork is the best it
  can be, there are several colour separation
  techniques that you can use

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Spot Colour Separations

• Spot colour separation is the most often used and
  the most basic method of colour separation. It is
  used when the artwork is made using solid colours
  that do not have intricate photo-realistic colour
  variations or tonal variations also referred to
  as gradients. You can do these with software such
  as Adobe Illustrator or Adobe Photoshop. The idea
  behind this is that every colour is lifted from
  the artwork, placed into its own separate layer
  within the layer palette of the adobe program
  that you have used, converted into a black
  infill, and then finally labelled with the
  registration marks and colour information before
  they get printed onto acetate film or for the
  screen room. The best part is that every colour
  fits snugly and perfectly next to the other
  colours you have used with no overlap.

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Process Colour Separations

• This type of printing requires four colours to
  make multi-coloured designs with hundreds of
  colours. Process printing is usually referred to
  as CMYK printing with the letters representing
  Cyan, Magenta, Yellow and Key. All the pictures
  that you see in magazines are printed using this
  type of printing, and you can even see a variable
  pattern of small dots if you hold a magnifying
  glass up to these pictures.
• The resolutions that are achieved using modern
  digital paper printing presses are much better
  than the resolution achieved using screen
  printing. Plus, these dots are also difficult to
  spot with the naked eye in a magazine, however,
  they can be easily seen on a t-shirt. The reason
  for this is that the output resolution to the
  film needed to burn a screen cant be more than
  65 dpi or LPI. This depends on the restrictive
  capabilities of the processes and chemicals
  employed in screen making for screen printing.

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• Process separations work incredibly well with
  white T-shirts, but they do not do well with dark
  t-shirts. The reason for this is that the process
  inks used for this procedure are a little
  transparent and the colour of a shirt that is
  darker will show through the ink printed on it
  and will affect the print colour. You can also
  try printing a white base under process inks, but
  you may get a washed out colour effect as a
  result, which will prevent your final image from
  looking the way you want it to. You can also
  augment process printing via spot colour printed
  in a halftone, so it can fit in the dot
  configuration of the process separations.
  Furthermore, you can never get Pantone accurate
  colours by using process printing. Plus, the
  majority of the skills in making a good print
  depend on the printer who is responsible for
  setting the job up, on the press along with good
  separations delivered by the artwork department.
• These separations are printed on a high mesh
  count screen. The screen is designed specially to
  hold detail. Typically, mesh counts of 90 holes
  per inch up to 140 holes per inch are preferred
  for this.

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Simulated Process Printing

• This process uses spot colours output to
  halftones similar to how the CMYK halftones are
  rendered.
• This is considered a better option than CMYK
  separations for complex, tonally rich t-shirt
  printed graphics as it produces bright, vivid
  colours regardless of the t-shirt colour. A white
  under-base is required along with experience and
  skills to understand the process and separate
  correctly. Photorealistic images can be achieved
  with this process which can sometimes be called
  channel or tonal separations.
• These separations are printed on high mesh count
  screens that are designed to hold detail. Mesh
  counts of 90 holes per inch up to 140 holes per
  inch are typically used.

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Index Colour Separations

• These are also known as diffusion, dither, or
  stochastic. This type of method uses tiny
  randomly spaced squares instead of ellipses or
  dots to make the tonal variations. The small
  squares are printed next to one another instead
  of overlapping like simulated or process, process
  printing. As a result, you get a jigsaw effect
  which results in tonal variations.
• If you look at it closely, you can spot that the
  image has a posterised look which cannot be
  seen if you move away. The human eye cannot
  usually detect this effect and, so the image
  appears tonal and variable.

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When To Use What Spot Colour Separation?
(Conclusion)

• Spot colour separations vary depending on the
  design since the majority of artworks are solid
  coloured images or consist of simple text. When
  you are working with a variable and tonally rich
  design, then you will have to go with simulated
  process printing. The only limitations to this
  method are budgetary.
• If you have a budget that lets you use only 4
  colours, and you are working with white t-shirts,
  then CMYK is your best fit.
• If the design you are working with is tonally
  variable but also has a high contrast effect
  requirement, then you may have to go with INDEX.