What’s The Difference and Why It Matters
In the world of graphic design, there are many terms of the trade. Some of the most important in relation to garment decoration and heat transfers are ‘Raster’ and ‘Vector’. Perhaps you’ve heard of these before, but maybe you don’t know exactly what they mean. Well in this article we will explore the meaning of these terms and how it affects you, your business and customer satisfaction.
What do the words Raster and Vector mean?
These are generic names or types of digital artwork files. Both Raster and Vector files are used in graphic design and are essential to producing various sorts of garment decoration. Vector and Raster files come in a variety of formats and can be created, edited, and read by many different programs. We will talk more about specific file formats later (or you can skip down to a list of common file formats).
What’s the difference between Raster and Vector files?
Raster files are based on tiny squares (called pixels). These pixels are arranged into a grid, called a Bitmap. Each pixel is filled with a color, hue or shade. When put together in the grid or bitmap, the thousands of tiny squares make-up an image or photo.
Vector files are based on lines, rather than pixels. These lines are defined by mathematical formulas. Every line or curve in a vector file include ‘nodes’ which assign the lines their length and shape. Lines can be given a color value, and when they connect to form a shape (like a circle or square) the inside area of that shape can be assigned a color value as well.
Raster or Vector – Why does it matter?
There are advantages and limitations to each of these file formats. Here are the main advantages and disadvantages for each:
- Advantage – Raster files are great for photos and complex graphics where there are undefined lines, blended gradients and other fine details. Raster images are also easily displayed and compatible with almost any device (computer, tablet or phone). This is why Raster is the most common and standard file type for use on the web.
- Disadvantage – When a raster image is created, it has a set number of pixels. If you try to enlarge that image or zoom in, the number of pixels don’t increase. So your image can look blurry and the edges look jagged because you can start to see the individual pixels. This is called ‘image degradation’. So why not just save the original image at a huge size to make sure you don’t lose quality when enlarging it? While this is an option, it comes with a price. Because the larger the image is, the more pixels there are, and that means more information to save in the file. So the larger the image, the larger the file size (some files can take up gigabytes worth of space). These larger files take up more space on your computer, are slower to display or print, and take longer to send electronically.
- Advantage – Vector files are great for logos, fonts and other computer generated illustrations. Since Vector images are defined by mathematical equations, they can be sized and scaled repeatedly and limitlessly without losing any resolution. Also, because there are no set number of pixels to save, Vector files are much smaller than their Raster counterparts. Therefore, they take up less space on your computer, display and print quicker, and are quicker to send electronically.
- Disadvantage – While vector files are great for solid colors, there are limitations to the amount and kind of shading, blending and gradient effects these files can achieve. There is no such thing as a ‘vector photo’. All photos are raster format (unless you make a vector illustration that looks like a photo, as the example above shows). Also, depending on the format the vector file is saved as, you may need a specific program to open it. Typically, most people won’t be able to open a vector file unless it’s in PDF or SVG format, so viewing these files can be a little more difficult than raster files.
Comparison
Which files are best for decorating garments?
Here are the different file formats used for each garment decoration process:
Screen Printing / Silk Screening
- Vector (.AI, .CDR, .PDF, .EPS, and others) Vector files are perfect for screen printing.
- Raster (.PSD, .TIFF, .JPEG, and others) beware when using Raster files, as a low quality file will mean a low quality print.
Heat Transfer Vinyl (solid color – not printable)
- Vector (.AI, .CDR, .PDF, .EPS, and others) Vector files are the only option for cutting HTV graphics.
Heat Transfer Vinyl (full color printable)
- Vector (.AI, .CDR, .PDF, .EPS, and others) Vector files are the ideal choice for Printable HTV because of their high quality and ability to create ‘contour cutlines’.
- Raster (.PSD, .TIFF, .JPEG, and others) While Raster files can be used to print onto HTV, you will still need a Vector ‘contour cutline’ to cut around the image.
Direct To Garment (DTG)
- Raster (.PNG, .TIFF, .JPEG, and others) Beware of White and Transparent backgrounds. JPEG files always have White backgrounds and can cause your DTG printer to print a white box around your image. TIFF and PNG files have the option when saving to ‘preserve transparency’ so you don’t get that White background.
Sublimation
- Raster (.PNG, .TIFF, .JPEG, and others) Most sublimation software programs accept raster files. Just make sure they are high quality/resolution or very large in size.
- Vector (.AI, .CDR, .PDF, .EPS, and others) Vector files are ideal because if there are spot colors or colors outside the printing gamut, these can be identified and replaced or changed.
File Formats
While this list does not include every format for each file type, these are the most common you will see in the graphic design world:
RASTER
- JPEG/JPG (Joint Photographic Experts Group)
- GIF (Graphics Interchange Format)
- PNG (Portable Network Graphics)
- BMP (Bit MaP)
- TIFF/TIF (Tagged Image File Format)
- PSD (PhotoShop Document)
VECTOR
- EPS (Encapsulated PostScript)
- SVG (Scalable Vector Graphics)
- PDF (Portable Document Format)
- AI (Adobe Illustrator)
- CDR (Corel DRaw)
- DXF (Drawing eXchange Format)
BOTH RASTER & VECTOR
- PS (Post Script)
- AI (Adobe Illustrator)
- CDR (Corel DRaw)
- EPS (Encapsulated PostScript)
- CDR (Corel DRaw)
- PDF (Portable Document Format)
There is a whole lot more info on these file types and formats that we will discuss in the future. Check back for more articles that will go into further detail. If you want to know more now, just do a search online. Or if you have specific questions, especially in regards to garment decoration, feel free to ask our graphic artists at:
