Our lesson today is going to be a little different. I’m going to tell you how to prepare a design for printing on T-shirts. This tutorial can be safely applied to printing on mugs, shirts, bags, caps, and other paraphernalia. But first, I’m going to tell you a little bit about ways to print on textiles in general. Then we’ll draw our design and prepare it for t-shirt printing from start to finish.
Types of printing on t-shirts
Conventionally, printing on materials can be divided into the two most popular categories – thermal applique and thermal transfer.
Thermal application is used to print vector images on textiles. The printing process is as follows. Images are cut out of a special film. The film is a colored rubber base, which can be present both in pure form, and with refinements, like velvet, luminous surface and so on. Next, the printing plotter cuts out areas of the graphic based on the vector image. Superfluous details are removed from the image. This process is called sampling. The film is then transferred to the textile and refilled with a thermal press. After cooling, the mounting film, which is the base of the material, is removed. If the image is multicolor, the entire process is repeated. That is, all the design elements for all colors are cut out one by one. This technology is popular primarily because it takes a minimum amount of time and allows you to minimize the circulation down to one copy. And, of course, you have already understood that we are talking exclusively about vector images and designs with a minimum number of colors.
For the printing of raster photos on textile materials digital thermal transfer is used most often.
Thermal transfer is suitable for raster images. In general, you can thermal transfer an image as a bitmap as well as a vector image. It makes no difference to the thermal press. It will print everything the same way. The vector image will essentially be “rasterized” and transferred to the t-shirt. The process is as follows. You prepare a file in any graphics editor. Of course for the highest quality resolution standard requirements for printing – 300 dpi and so on. Next, using the cutting plotter from the image cut out the shape you need. We get a working transfer, which is applied to the T-shirt under the thermal press. The backing is then removed. If the image is multicolor, the process is repeated several times for each color channel.
This printing process does not cause any difficulties for designers familiar with printing and preparing to print business cards, flyers and other paraphernalia. In essence, the process is identical. And that is why we will talk about a more complicated, more resistant to washing and high-quality process of applying images to textiles – thermal applique.
File formats
Now we’re going to talk about the work area for t-shirt design and the requirement for files. First of all, all printers have their own technical requirements for the designs used. So you should definitely read them. You can create a vector image in any vector editor, adapted for this. A number of printers require files in AI, CRD, EPS, PSD format. Many printers have restrictions on software versions. For example, you have to save the file in AI format, which is compatible with the 9th version of Illustrator. If you have neither Corel Draw, nor Illustrator, a vector editor must be able to save files in the standard EPS vector format.

Working Area and Dimensions
Creating a working area based on the actual size of the design. That is, take a ruler, put it to a powerful chest and really figure out the size of the elements of the film. Film printing is not capable of printing lines less than 0.8 mm wide. Such lines will simply tear away from the t-shirt, or fall out when printed, or you simply won’t have the layout accepted. Therefore, if you have text planned in your design, consider the width of the lines. The same goes for various grunge ornate patterns and blots.
Let’s open Illustrator and create a working area of 30 by 30 cm. The other settings are not important to us.
Create a t-shirt design
For the t-shirt design, I chose an image of cream, from which we will create something of our own. Place the cream image on the workspace via File > Place. The picture will be our base. So convert the layer it’s on to a temple.
Double click on the layer that the image is on and in the dialog box select Dim Images to and Temple. After that, create a new layer and work on it.
Now select the Pen Tool and start outlining the cream jar. You can read about how the Pen Tool works in the articles Pen Tool in Illustrator and Drawing Pen Tool in Photoshop. To see what’s happening on the work surface, I put a thick red border and a transparent fill.
The first figure is drawn. Now let’s draw the cream. Let’s do it in exactly the same way with the Pen Tool.
The design for a thermal appliqué doesn’t have to be complicated.
Working with text
Now let’s add some text. Let’s write some Photoshop lettering. I chose the font Myriad Pro.
Now the second inscription is the “secret of success”. The font: Georgia Bold with a slant. The Nivea backing can be turned off, or removed altogether. And the image is slightly transformed to fit on the workspace. Moreover, I reduced the distance between the letters. This can be done in the Character panel. The way I see it, the letters should just go together.
My next step is to translate the text into curves. We will need very simple vector shapes to print the design on the t-shirt. Select both lettering with the Selection Tool and choose Type > Create Outlines
The Photoshop lettering sits too flat on the cream jar. But it should be at least a little around it. This is easy to correct. Select the inscription and go to Object > Envelope Distort > Make with Warps. In the dialog box, check Preview to see the result. Curve the inscription downwards, and warp it slightly vertically. In the bend mode select Arch.
At this stage we have two objects with text. Broken pieces stacked in a group from the inscription “The Secret of Success” and the Photoshop inscription, which is a complex object Envelope Wrap. We need to get rid of all the complex objects, break them into curves and combine them into simple shapes. Groups are also forbidden.
Let’s start with the Photoshop caption. Select the object and break it into curves Object > Expand. We got the details of the caption folded into a group. Now turn on Curves View > Outlines and work with our vector outlines. I want the letters to not touch each other, but overlap each other. We’ve already done that work by reducing the distances between the letters, and now a bit of manual correction. The point is that next we have to merge all the letters into a single shape, and if somewhere the contours do not overlap each other explicitly, we will have a problem.
Select the Direct Selection Tool, and adjust your points.
In the area where the letters U and R intersect, I removed the extra points with the Pen Tool, and aligned the letter trunks with each other.
Now we need to connect all the letters together by getting rid of the partitions. I open my Pathfinder and use the Unite command. But that’s not enough. The shapes do merge, but the “success” part of the word does not intersect with the rest of the shapes in any way. So Pathfinder merged them into a group.
It is necessary to get a single fused vector object instead of a group. Let’s create a compound object through Object > Compound Path > Make or CTRL+8 Do the same operation with the word “Photoshop”. Finally, you should have 4 shapes. The jar, the cream, and the two complex lettering.
Now let’s move on to the t-shirt design layout.
Trapping when creating a t-shirt design
When working with conventional printing, you don’t have to think about “cutting” the graphics when you overlay one ink on top of another. The illustrator itself will separate your colors as needed. If you draw a C100 blue area and an M100 magenta area on top of it, the process will be on different color channels. So the magenta square will need to get into the slot that’s freed up for it. That is, plates with different layers of paints will overlap, and the joint of the paints may not come together. Roughly speaking, the square will not fit exactly into the hole and white gaps will form. The gaps are solved by trapping. When trapping, you create a small border up to 0.5 pt in width around the object. The trapping is set to Overprint mode. That way, it lays on top of all paint layers, “blurring” the white gaps.
The problem is most relevant with black paint, because black is in a separate channel and is used most often, including on surfaces painted in a different color. In this case, applies Overprint, the essence of which is that the black channel is printed on top of all, without cutting holes. In this way it becomes, of course, more saturated and takes on a hue, but it is hardly noticeable. But in conventional paper printing, you don’t have to worry about trapping.
When preparing a vector design for thermal appliqué, it’s completely different. First of all, you don’t have any trapping. You just create vector outlines that will be cut from the film. When you’re preparing your design you need to know what kind of film you’re going to print with. But we’ll talk about color below. Automatic “cut out” graphics won’t happen either. If you create a design from a blue area over which a magenta area lays, the magenta area will lay on top of the blue area without a hole cut. This means only one thing to the printer: unnecessary waste of valuable film. Your design will not be accepted in this form, so we will make the hole by hand. It’s not easy with edge alignment either. You have to manually trapping each object so that the paint layers slightly overlap each other.
Cut out the holes of the design
First, let’s trim the can and the cream. Select both objects, open the Pathfinder panel and click the Minus Front command. But before that, copy the cream CTRL+C, and after the hole is cut, put it in the same place CTRL+F. The objects will be stacked in a group. We don’t need it, get rid of it Object > Ungroup. In the image below, I’ve intentionally shifted the shapes to make it clear what we need to get.
As required by the printer, the objects should slightly overlap each other by at least 2 mm. This distance varies by the way. Be sure to read the requirements of the printer to prepare for printing. The layers should overlap each other in descending order. That is, a large layer goes first, with smaller layers on top, and so on.
Select the cream and the Object > Path > Offset Path command. In the dialog box, set 2 mm. The command creates a copy of the object, so the old object can be deleted.
Now it is the turn of the Photoshop inscription. We choose a jar and an inscription. The inscription should be above the can. In the Pathfinder panel, select the Minus Front option. As a result, we have a group, combining elements of the graphics. Let’s merge everything together through Object > Compound Path > Make
We got rid of the Photoshop lettering by cutting a hole in the can through it, but where is the lettering itself? If the design is going to be printed on a white T-shirt, we don’t need white. But what if the color of the T-shirt is arbitrary? In this case, we just need another layer with a film in the form of an inscription overlapping the holes in the cream jar.
Select the Group Selection Tool and select only the hole with the Photoshop inscription. Now press CTRL+C and CTRL+F to copy the inscription to the same location on the work surface. The outlines will be copied unfolded, so we’ll have to assemble the lettering. Select each letter that has notches in it, and cut the holes with the Minus Front command from the Pathfinder panel. The visibility of the rest of the objects can be turned off so they don’t get in the way. After all that, merge the inscription through Object > Compound Path > Make
We’ll apply Object > Path > Offset Path mode to the inscription and shift its outline by 2 mm. This command creates a copy of the object, so the old inscription can be removed.
Checking Layout Contours
There shouldn’t be anything unnecessary in the design for the t-shirt. Scattered vector dots, vector trash. All this is excluded. You can check the layout in the outline view View > Outline
As you can see, everything is clear. The contours neatly overlap each other, there are no unnecessary intersections. It is especially useful to check for vectorial trash on the tracing graphics.
Merge layers
When preparing a design for a t-shirt, you need to understand that the print shop will require a specific number of films to print. Each color of your design is one film. It is unacceptable to create different objects of the same color. According to the idea of our design the jar and the inscription “secret of success” will be blue. The Photoshop inscription is white and the cream is yellow. In total, we need only three vector fused objects.
Choose the “secret of success” inscription and the jar and merge them together through Object > Compound Path > Make or CTRL+8
Choosing the colors of the design foils
We’ll use ProstoPrint.ru and choose a color from the list of available films. So how to make the work of the printer as easy as possible and let him understand exactly what color we mean for each object?
First of all, I will go to the Swatches panel, select all the colors and delete them. Then I will create new colors. In the dialog box, we adjust the approximate color of the film and enter the exact name of the paint from those offered by the printer. In the paint settings we select Spot Color.
And then I create 3 inks from the list of inks of the printing house, each of which has a corresponding name. It only remains to set the cream jar with the correct color.
That’s it. I hope you got some useful information from this tutorial.