First, you have to know the difference between vector and bitmap images. Bitmap (also known as raster) images are composed of many small dots, or pixels, which combine to create an image. Bitmap files types include: JPEG, GIF, and PNG (though PDFs are typically vectors, they can be bitmaps). Bitmap images are problematic because they are composed of small dots, and therefore they cannot be resized without compromising the image quality. When you increase the size of a bitmap image you are just enlarging the pixels, and once they become a certain size the individual pixels become distinguishable- thus the term “pixelated.”
To avoid these issues, you must save bitmap images at the exact size necessary for your design. Otherwise you will run the risk of a low resolution print. In a low resolution image there are 72 dots per inch (DPI). Most internet images are 72 DPI. To be digitally printed (sublimation, direct-to-garment, wide format), an image should be at least 300 DPI. Having a higher DPI allows for sharper images with greater detail that will jump off of whatever surface they are printed on.
Vector images, however, are more flexible. Vector images are created through mathematical formulas, rather than pixels, using lines and curves to create images. This allows vector images to be resized without issue, and makes them the choice for images that need to be resized often. For example, your business logo ought to be saved as a vector image so it can be used to print on a wide variety of media to promote your brand. EPS, AI, and PDF are common vector image types. Vector images can be saved as bitmap images, but bitmap images cannot be saved as vectors.
A good way to think of the difference between the two is the vector should be your “source file”- the original from which you can save and create bitmap images in the exact size necessary for a specific print. Also, it is difficult to vectorize photographs or full-color images, so vector images are great for logos and similar images. However, photographs and images with a large number of colors should be saved as bitmap files.
Screen Printers typically prefer to work with vector images for several reasons. First and foremost is the aforementioned capability of vectors. It takes far less time and effort on the printer’s behalf to adjust vector images. Also, vector lines are much smoother since they are actual lines rather than a collection of pixels, and it creates a smoother print. If the screen printer is performing the color separation, then vectors are much easier to color separate. The colors in a vector image are constrained, whereas in a bitmap image the colors are spread among thousands of tiny pixels. Using vector artwork for screen printing ensures the highest quality print.
Direct-To-Garment, Sublimation, and Wide Format Printers use CMYK inks to print full color images. The higher the resolution of an image, the higher the overall print quality will be. Since these printers use CMYK ink, the image does not have to be created using design software (like for screen printing) and can be most digital file formats. However, bitmap PDF, PNG, EPS, JPEG, & PSD at a high resolution, or AI, EPS, PDF, & CDR vector images work best. The reason digital printing is more forgiving for artwork than screen printing is because each color does not need to be separated, and the CMYK print heads can easily create any color. While digital printers can print low resolution images, higher resolution images (300+ DPI) will always print better because there is more color information within every square inch of the artwork.
Embroidery requires that a design be digitized from a vector format. Digitizing requires special software and sets up the sewing sequence for stitches to create the design. Embroidery machines must have a digitized design in order to know where and how many stitches to sew into the product. .DST and .EMB are the two most common digitized file formats. Fiverr.com is an excellent resource for digitizing artwork, as most files can be digitized for as little as $5.00. Just be sure to find a digitizer who has good reviews.
Manipulating digital artwork is one of the most important parts of a decoration business’s operations. Without well-prepared artwork it will be impossible to print or sew high quality designs. So, for a new product decoration business, it is important to take the time to learn all the ins and outs of digital artwork manipulation that apply to your decoration processes. Manipulating digital artwork can be difficult and time-consuming, so save yourself and your customers the headache by mastering the process.