File Types & Terms
Raster images are made up of pixels, dots of color that work together to form the image. Photographs are always raster files, as well as most images you see online. Raster images will gradually lose quality as you scale them up, creating a rough, pixelated appearance.
Vector images are not comprised of pixels. Instead, they use math equations to determine the appearance of the image. Because of this, vector images can be scaled up or down to any size and they will never decrease in image quality, which makes them ideal files to send to be printed in large formats.
Every raster image is made up of pixels; single dots of color that, together, form the image. As an example, a 2-megapixel image has 1,920,000 pixels (1200x1600).
A JPEG (saved with the extension .jpg) is the most common file type for an image. Most digital cameras take a .jpg image by default. This is a raster file format that uses color compression to reduce the size of the image file. The compression amount can be adjusted, but .jpg files typically achieve a 10:1 reduction in file size with very little noticeable loss in image quality.
A TIFF file (saved with the extension .tif) stands for Tagged Image File Format standard. This is a raster file that can be saved uncompressed without any degradation of the image.
An EPS file retains the information of a vector file. This means that .eps images can be scaled to any size without loss of image quality. This is a great file type to send to be printed, especially for large format prints.
Color profiles are generated for printer and paper combinations so that accurate reproduction of colors is possible. They are also very useful in obtaining color matches between monitors and printers to ensure that what is seen on the screen is an accurate representation of the final printed image.
RGB stands for the Red-Green-Blue color profile. This is typically used in monitors and digital cameras. Colors are defined by the levels of red, green, and blue measured on a scale from 0-256: therefore, pure black is 0-0-0 and pure white is 256-256-256.
CMYK refers to the Cyan-Magenta-Yellow-Black color profile, usually associated with four-color printing. Each color is measured on a scale from 0-100. CMYK is a subtractive color scale, so pure black is 0-0-0-100 and pure white 0-0-0-0.
DPI stands for dots per inch, and refers to the number of pixels within one square inch of an image. A higher dpi results in a higher quality image. The dpi that an image needs to be depends on the size of the print and the distance it will be viewed from. In offset printing, such as magazines or newspapers, 300 dpi is the standard. In large format printing, the dpi can be much lower.
Resolution expresses the image quality, and is defined by pixel density (dots per inch) or image size (pixels tall x pixels wide).
Raster images are often resampled when being enlarged in order to lessen the noticeability of pixelation. Resampling can “soften” images, particularly at sharp borders between colors, but when done by a knowledgeable professional it can enlarge an image with very little loss of image quality
Printing Process Terms
This is a process that covers a print with a protective layer of hardened plastic or liquid. There are many laminating techniques available, in both hot and cold applications.
Fine Art Reproduction:
When reproducing fine art, great care is taken to match colors and details precisely, to accurately reproduce the original work.
A term used to describe high-quality inkjet prints, most often associated with fine art reproduction.
These inks are resistant to UV light, making them much more fade resistant than ordinary ink. All of GH Companies’ inks are archival.
This printing process uses inkjet technologies to produce an image, requiring no printing plates or silk screens. This allows variable data to be used to customize each image, and makes for more affordable printing of short runs, especially in large format sizes.
Offset Printing separates an image into 4 plates, one each of Cyan, Magenta, Yellow, and Black color values. Each plate transfers its part of the image to a rubber blanket, which then imprints the paper. This produces a consistent, high-quality image that is more crisp and clear than what digital printing can produce.
Thermal Inkjet Printing:
Ink drops are expelled from a print head by generating a small bubble of steam with a pulse of electricity.
Piezo Inkjet Printing:
Ink drops are expelled from a print head by the activation of a piezo crystal with a pulse of electricity. These print heads are more expensive, but generally last much longer than thermal print heads.
This refers to inkjet printing with piezo print heads and inks that use a solvent instead of water to carry the pigments. The solvent evaporates off of the surface, leaving only the pigments. These pigments are not water soluble, making the output waterproof. This is a common process for making outdoor banners.
Flatbed Printing uses a digital inkjet printing process to print directly to flat sheets of material, such as coroplast, sintra, 50 point board, and styrene.
Dye Sublimation Printing:
This is a digital method to create custom printed fabric. First a mirror image of the artwork is printed on a special paper; then the paper and fabric are run together through hot rollers to transfer the image to the fabric.
UV Curable Inkjet Printing:
This process uses UV lights on either side of the print carriage to cure the inks deposited on the substrate by piezo print heads. One advantage of this process is that it can print of flat sheets, and it is the predominant technology used in flatbed printing. It can also be used to apply an image directly to fabric.
Digitally Printed Wallpaper:
Wallpaper in short runs can be done very effectively with UV curable printing equipment. The material has exceptional durability and the artwork is beautiful and vibrant. Photos or digital art can be expanded to wall size for striking results in both commercial and residential applications.
Products and Materials
Foam Core Board:
Your artwork is printed on a piece of paper on either side of a thickness of Styrofoam. This product is perfect for short duration signage, such as meeting and event signs that will stand on an easel, but isn’t recommended for permanent displays.
This is similar to the foam core board, using the same process of displaying artwork on either side of Styrofoam. But Gatorboard is a branded product of International paper that uses moisture-impregnated paper for a more durable, high-quality result.
This is also similar to Foam core board, except with sheets of styrene on the Styrofoam rather than paper. It is much less susceptible to warping from humidity changes.
Styrene is a plastic product used extensively in sign making due to its low cost, durability, and ease of cutting.
Sintra is a foamed PVC board used extensively in sign making. It is often used outdoors because of its resistance to rain, wind, and sunlight. It comes in thicknesses up to 1.5”
Often called “plastic cardboard”, coroplast is made of a fluted polypropylene plastic material. It is an affordable, lightweight, sign-making product.
50 Point Board:
Named for its thickness of .050”, 50 Point Board is a 100% recycled board commonly used for 22x28” signs that will be fit into sign stands. It can also be recycled with cardboard.