How should artwork be setup for T-shirt printing?

Question

1. What does it mean to colour separate the artwork for T-Shirt printing?

2. It is normally suggested to use Pantone colours for T-Shirt printing. Is it the Pantone Coated or the Pantone Uncoated? The Uncoated one has more subtle colours and we can't choose brighter shades if the design requires that. What is more appropriate for printing?

3. Can we use gradients in T-Shirt printing or is it suggested to stick to flat colours only?

The reason for asking if gradients were ok was to use it as an option for this design:

I was considering it an option, as it will be difficult to colour separate since the textures are clip masked inside the lion.

Answer 1

Color Separation

This is the process of taking the artwork and (for the lack of a better term) separating the colors to facilitate the creation of the individual printing plates. To show by example, here's a 3 color job:

Your printer probably won't expect you to create the plates with the trim and registration marks^†, but you can certainly help them out by separating the colors yourself. The best deliverable for your printer is a file with all the colors already separated onto their each layer like so:

Each of the three layers is labelled and only contains shapes with their respective colors. My answer here should help you with that process.

Pantone Solid Coated vs. Uncoated

This is largely irrelevant when it comes to printing on apparel. PMS C and PMS U are both mixed together from the same 14 base colors and they use the same formulas for each color. The coated vs. uncoated relates to how the ink will appear on coated or uncoated paper and doesn't apply to fabric.

Take a look at this picture I took of PMS 299 in the coated (left) and uncoated (right) mixing guide:

If you look closely at the mixing ratios you'll see that they're exactly the same. PMS C and U will look different on screen (and in these books), but that won't make a difference when it comes to actually mixing the ink and applying it to the fabric.

Gradients

Spot color cradients can be achieved with halftones, and this is something I would advise you to work with your printer on. Halftones can be tricky and need to be set up properly (proper halftone size, PPI, frequency, angle). To give you an idea how how a screen-printed gradient would look, here's an example:

This graphic uses only two spot colors (yellow and red), but from a distance it will have the appearance of a smooth gradient.

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^{† The registration marks are used for the initial setup of printing to properly align each of the screens. I added them to show you exactly what the printing plates could look like for that artwork. This is something that your printer would add themselves when they create the plates, you don't need to worry about including them in your artwork. Speaking as a printer, if someone included registration marks in the artwork they sent me, I would probably replace them with my own marks that I'm accustomed to using. Separating the colors into different layers is all you should worry about.}

^{Swallow graphic courtesy of publicdomainvectors.org}

Answer 2

My answer applies to silkscreen printing only so make sure that's the kind of printing you are dealing with before using this information and also double check the specifics with your printer, better safe than sorry!

What does it mean to colour separate the artwork in T-Shirt printing?

Like in many printing methods, silkscreen printing prints one color at a time. For example, if you have an image that is in CMYK to print on a white tshirt, a color separation would involve to separate the cyan, from the yellow, from the magenta and from the black. The colors can be solid or halftoned. You can view something similar when you check your color separations in Illustrator or InDesign.

It is normally suggested to use Pantone colours for T-Shirt printing. Is it the Pantone Coated or the Pantone Uncoated? The Uncoated one has more subtle colours and we can't choose brighter shades if the design requires that. What is more appropriate for printing?

Ultimately, each color separations is printed in black and white to expose each screen that will be used to print the tshirt. In the end, the printer will use a color that fits with what you've specified but there is no concept of coated/uncoated as the inks are different. You could use a specific spot color in your design (let's say magenta) and ask the printer to use the magenta to print a "glow-in-the-dark" ink or something weird that only silkscreen can do. What is important is that your colors are spot colors so they will separate properly.

Can we go for gradients in T-Shirt printing or is it suggested to stick to flat colours only?

You can do gradients in silkscreen but the halftone is more coarse than on print so it will show if you look up closely. Some people experiment with mixing inks directly on the screen but that is not likely if you are getting something commercially printed.

A very important reminder: don't forget that white is a color in silkscreen. So if you are printing on a red tshirt and that your design has some white parts, you will need to consider this. Also if you want to print a CMYK image on a shirt, you will need to "flood" the area first, this means to put print a white surface before printing on top.

Answer 3

What does it mean to colour separate the artwork in T-Shirt printing?

To color separate the artwork means the printer will typically isolate CMYK or the pantone colors for one plate/screen. This typically depends on the design and the printer. If you're printing a shirt with a DTG printer than separation is typically not needed unless printing on a black shirt. If you are printing on a black shirt its known to print a white base coat to make the colors stand out on black. If you are not having the shirts DTG printed and are on the route of screen printing you may be required to provide the artwork separated or some require each color on a layer with a master layer of how the design looks. This stage depends on the printer and what they are wanting to print. Some printers do have a design department but there may be a fee associated with getting your artwork ready.

Example:

It is normally suggested to use Pantone colours for T-Shirt printing. Is it the Pantone Coated or the Pantone Uncoated? The Uncoated one has more subtle colours and we can't choose brighter shades if the design requires that. What is more appropriate for printing?

To choose the color you want you will have to reference the guide so it will depend on the color you're looking for. Some printers do use Pantone Coated more than uncoated but a true printer will have all the books. I would suggest going in and talking with the printer and choosing the colors you want. Choosing over the internet is not a wise decision and sometimes the color displayed is different than what is seen. I would consider if you need Pantone colors due to the increased in printing costs. I use this as an example. If you are Coca-Cola and you are ordering 1000 shirts and you want your signature red color which I believe they get in a special Pantone color printed on every shirt then you would order it. If you are an individual with a logo that requires 6 Pantone colors you will pay a larger fee than printing it CMYK but printing in 6 colors can be done. It just depends on how much you want to spend and how exact you want your shirts. So this depends on your design and the printer.

Can we go for gradients in T-Shirt printing or is it suggested to stick to flat colours only?

You could go for gradients in DTG printing but they sometimes appear washed out and that depends on the machine but if you are going to be screen printing you will want to change your gradients to Halftones.

A few reference Q&As here that we have:

• What should you ask the printer?
• Simple Spot Color Separations for Screen Printing
• How to image trace halftones in Illustrator
• How can I create a circle fill effect similar to a halftone in Illustrator?
• What printing process is better to avoid t-shirt logo damage?

There are three main factors to consider when printing:

1. Cost
2. Quanity
3. Life

All three of these play a role in which may be the ideal printing solution. If you go DTG it is best for small runs typically under 25 but the life of a DTG shirt will fade compared to a silk screened shirt. Silk screen shirts are for larger runs of 25 or more. However, the cost for 10 shirts on a DTG printer may come close to the cost of 25 screen printed but that depends on the design, ink, and printer. Just something to consider.

Answer 4

There is no such thing as coated and uncoated Pantone colors. Coated and uncoated is only a reference for designers so they will have an idea what the colors will look like when printed on coated or uncoated paper stock. Colors tend to appear brighter on a coated stock and duller on an uncoated stock. The Pantone color swatch books and computer software simulate the effect coated and uncoated paper stock will have on the inks when printed on these types of paper. So it won't matter which version of Pantone colors you select when creating a design to print on a t-shirt.