The Difference Between Raster and Vector Images  | Screenprinting.com

Creating designs for screen printing takes a little bit of work and creativity. Whether you’re designing a logo for your brand or creating a t-shirt design based on artwork from a client, you’ll need design software that works for you. But before you get to designing, you need to know the difference between raster and vector images. 

An image in Adobe Illustrator reading "Buy Local"

WHAT IS A VECTOR IMAGE? 

Screen printers use vector images. A vector image uses mathematical algorithms to create paths and curves. Sounds complicated, right? What this means for screen printing is that the image is infinitely scalable. You can zoom super far in on the image without it getting blurry. 

Vector images need to be edited in Adobe® Illustrator or a similar vector software. These types of images are preferred throughout the graphic design world, including screen printing. The lines stay smooth and crisp whether you’re creating artwork for an oversized back print or a business card. 

Examples of vectorized files are .ai, .eps, .svg, and .pdf (if in vector format).

A zoomed-in vectorized image with crisp lines

Vector images stay crisp and clean no matter how far you zoom in.

WHAT IS A RASTER IMAGE?

Raster images are made up of pixels. When you take a photo on your phone or a camera, that image becomes a raster image. You’ll know it’s a raster image because if you zoom in on the image, it becomes fuzzy.

These images are used mostly in photography. The file size is pretty large because of the amount of pixels making up the photo. The more pixels, the higher quality the image will be. Raster images are not recommended for any sort of graphic design because you can not resize them without making the design blurry. File names of raster images include .psd, .pdf, .jpg, and .png, to name a few.

Raster images can be edited with Adobe® Photoshop, Procreate, and Lightroom. If you don’t have these programs, don’t worry. If a client sends you a simple, high-resolution, rasterized image, or you have a raster image you want to use in a design, you may be able to vectorize it.

A zoomed in rasterized image that has fuzzy lines

Zoomed-in raster images look a little blurry on the edges. 

VECTORIZING A RASTER IMAGE

If you have a simple, high-resolution raster image that you want to create a t-shirt design with, don’t worry! Golden Press Studio’s art director Cory Romeiser walks you through the steps in the free Adobe® Illustrator class. The chapter featuring this topic is called “Image Trace.” Cory uses a one-color, high-res raster image exported from Procreate. 

RELATED: WHY PRINTERS NEED TO MASTER ADOBE ILLUSTRATOR FOR SCREEN PRINTING

SETTING UP

In the course, Cory created a design in Procreate and uploaded it into Adobe® Illustrator to vectorize it. If you followed along in the free Procreate class, you can use one of those designs. Currently, it’s a raster image. If you zoom in on the image, it’s pixelated. Click on “Image Trace” on the bottom right of your toolbar. If “Image Trace” isn’t in your toolbar, simply go up to “Window” and scroll to “Image Trace.”

Click on the image and hit “Image Trace.” Take a look at your advanced settings. Cory has his settings saved as a preset. His thresholds, paths, and corners are set to 97, and his noise is set to 1 pixel. He also has “ignore white” selected. 

WHAT DO THOSE SLIDERS DO?

Making subtle adjustments to your advanced settings in the image trace section actually can make a noticeable difference. Thresholds make the design thicker or thinner. The higher the threshold, the thicker the design is. Paths make the corners smooth or square. Cory’s paths are set at 97 because he wants smooth corners on his design. The percentage of noise in your design equals the amount of detail. This is a very slight adjustment, but if you play around with the slider, you’ll notice a little bit of change.

A vectorized image of the words "Buy Local" with anchor points surrounding the words.

FINISHING THE VECTOR

Once you’ve saved your advanced settings as a preset, hit OK. You might notice that the design doesn’t look much different. There’s still a bounding box around it. Go to the top of your screen and click “Expand.” Your artwork should have an outline all the way around, and should be anchored to vector points. 

Currently, the vector image is grouped. This means you can’t move individual pieces around. If you want to move, add, or delete pieces, simply ungroup the design. You’re ready to customize your vector design and get to printing.

RELATED: HOW TO CUSTOMIZE A DESIGN FROM A VECTOR PACK IN ADOBE ILLUSTRATOR

An image reading "Buy Local" with the "Y" highlighted

Raster images are used for photography and photo editing. They can’t be edited in Adobe® Illustrator, and aren’t recommended for screen printing. Vector images, on the other hand, are made up of anchor points so you can design and edit to your exact needs. The image is infinitely scalable, so you’ll never lose quality regardless of how big or small your design needs to be. Whether you’re creating a left chest print or a building-sized banner, vector images can get you there. Your only limit is your creativity.

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