Application
Applications (or so-called software programs) are executables designed to perform specific functions. Adobe PhotoShop® is an example of an application designed to perform image editing. Microsoft Word® is an example of an application designed to perform word processing.

Bitmap
A bitmap is an image format that defines an image only in terms of black and white. A bitmapped image is used normally for line art because its elements can only be black and white, unlike a greyscale image.

Color modes
Colour work can be produced (sometimes unknown to the author) in several different color modes. The actual colors within these modes are defined in a dimensional co-ordinate system used to describe the colors numerically, as values. Some models include Red, Green, Blue (RGB); Hue, Lightness, Saturation (HLS); Cyan, Magenta, Yellow, Black (CMYK); and Lightness, a, b (Lab).

Color space
A particular variant of a color model with a specific gamut (i.e. range of colors), which is one of its major characteristics. For example, within the color model RGB are a number of color spaces, like Apple RGB, Adobe RGB (1998), and sRGB. While each of these define color by the same three axes (R, G, and B), they differ in gamut, as well as other specific characteristics.

Combination Art
An image that is a combination of both a halftone and line art element. The most common occurrences are images where the labelling of the image is outside of the halftone area, or where there is a graph next to the halftone area. The requirements for this particular type of image are that the text is as clear as possible, with unchanged quality of the halftone. The only way to do this is by combining the properties of the two image types, and this normally results in files that are (significantly) larger.

CMYK
CMYK stands for the four-color printing process (process printing) that uses the standard inks Cyan, Magenta, Yellow and Black. It is also known as subtractive color. The color black is achieved by the presence of all inks. Basically, each color can be achieved by using Cyan, Magenta and Yellow, where Black is used to give correct neutral tones and to add detail.

Cropping
Cropping refers to the removal of any additional white space surrounding your artwork.

DPI
DPI is an acronym of Dots-per-inch (sometimes called Pixels-per-inch), the associated value of which gives the number of pixels that are defined within the boundary of an inch, and is often referred to as the resolution of the image. The more correct term is pixels-per-inch, but dots-per-inch is still used widely in the prepress/printing industry.

EPS
EPS stands for the Encapsulated PostScript format from Adobe. An EPS file is an image that has been created using the language of PostScript, and is generally resolution-independent because it has been created using vectors (unless it contains an 'embedded' bitmap image, like a TIFF file, then the TIFF file's resolution is restricted by its dpi). Because it is the vector that draws the image, the computer can draw the image at any resolution. The computer can thus determine at what resolution it is to draw the image (or portion of the image) on the printing device to which it is connected. An EPS file is normally used for combination artwork or charts and graphs.

Gamut
A gamut is the range of colors (or color space) available to a given device. Some examples of a device are: the human eye, a computer monitor or an inkjet print.

Some of these gamuts contain a far larger range of possible colors than others. For instance, a computer screen works with RGB gamuts, that are far wider than those used in the commercial printing world, where the more limited CMYK gamut is used.

GIF
GIF stands for 'Graphic Interchange Format', the standard was developed by Compuserve and is the predominant image format on the web today. This is an image format that is geared specifically towards computer screen representation. Its resolution is thus normally very low (72 dpi, or that of your computer screen), making it undesirable for printing purposes. In addition, GIF files also contain a maximum of 256 colors, thus making the format less desirable for presentation of photographic/halftone images.

Greyscale
Greyscale is an image type that defines how the information in the image is to be stored and imaged. A greyscale image is sometimes referred to as an eight-bit image. This format is generally used for halftones, because it stores the information for each pixel as a shade of grey. There are 256 shades of grey in a halftone.

Halftone
A halftone is an image, such as a photograph or micrograph. It is also the method of generating, on the printing press or on a laser printer, an image that requires varying densities, or shades, to accurately render the image. This is achieved by representing the image as a pattern of dots of varying size. Larger dots represent darker areas, and smaller dots represent lighter areas of an image.

Indexed Color
A color mode that contains a palette of 256 colors or less, to define the colors in the image. Indexed color can reduce the data file size while maintaining visual quality. The reduction in file size makes it an ideal format for multimedia or web graphics. It is not used for high-end printing.

Jaggies
An effect caused by images or lines being rendered at too low a resolution. It can be defined as a 'stair-stepped' effect, giving the line or image a rough appearance. By increasing the resolution, we can reduce the stair-stepped effect. It is important to remember that once an image has been saved at a lower resolution, it cannot be upgraded to a higher resolution. The physical resolution will increase, but the quality of the image will not.

JPEG
JPEG stands for 'Joint Photographic Experts Group'. JPEG is a standards committee that designed an image compression format. The compression format they designed is known as a lossy compression, in that it deletes information from an image that it considers unnecessary.

Line art
An image, such as a graph or bar chart, that requires sharp edges and high contrast between the areas of the image that have ink and those that do not . These images require a higher resolution to create the necessary sharpness. To be able to scale line art without loss of detail, the EPS format is usually used.

Moiré
A noticeable, unwanted pattern generated by scanning or rescreening a piece of art that already contains a dot pattern. This effect can also be caused by the misalignment of screen angles in color work.

Native Images
Native files are the default format generated by software applications (such as FreeHand, Illustrator, CorelDraw, Photoshop and Canvas) which can all be used to generate electronic artwork quickly and reliably. This application file is normally called the working file, and will have an application-specific extension (e.g. .PSD for Adobe Photoshop files).

Elsevier prefers to receive such files saved in either TIFF or EPS format.  The option to save in one of these formats can normally be found under either the 'File->Save As...' or 'File->Export...' menu items of all common graphics software.

PDF
Adobe's Portable Document Format is fast becoming a standard format for document exchange. It can be a very useful format for images, and may well become a preferred image format in the future.

Pixel
One of the small units that make up an image on a computer or television screen. It is derived from the words picture and element to make pixel.

Preferred Formats
Elsevier would like your artwork to be supplied in either TIFF, EPS or native MS Office format.

Virtually all common artwork creation software is capable of saving files as EPS. This 'option' can normally be found under 'the 'Save As...' or 'Export...' commands in the 'File' menu. MS Office applications do not have this facilty and should therefore be supplied in native format (i.e. Word, Excel or Powerpoint).

Process printing
Output based from a printing press that uses four colors, cyan, magenta, yellow, and black to create the illusion of continuous tone images. For that reason, cyan, magenta, yellow, and black are also known as process colors (CMYK).

PostScript (PS)
A page description language created by Adobe Systems Inc. that is a device-independent industry standard for outputting documents and graphics.

Raster
The process of rendering an image or a page using the technology that helped create television. It involves rendering the particular image or page, pixel by pixel, in a sweeping vertical or horizontal motion, like a rake drawing lines in the dirt.

Resolution
The resolution of an electronic file expressed as dots per inch (dpi). Elsevier has different resolution requirements based on the type of image supplied. Final (output) resolution for print can be anywhere between 300-3300dpi.

RGB (Red, Green, Blue)
Elsevier's preferred color 'format' for artwork. RGB is the color process used by computer displays. The presence of all three colors as lightwaves is perceived by the eye as white; the absence of light is perceived as black. This is also known as additive color. RGB color is very different from CMYK color. The amount of colors that can be generated by RGB mode is much larger than those that can be generated by CMYK.

Separation
The process printers use to break down a color image into its components of cyan, magenta, yellow and black (CMYK) for the purposes of printing. An image that has been processed this way is also known as a separation. The separation consists of four halftones that represent the four inks used on press to recreate the image.

TIFF (Tagged Image File Format)
A type of image file format, TIFF can include color or greyscale information. Its resolution or dpi determines the quality of the image. If the resolution is too low, the image will appear jagged or have a stair-stepped effect. Once the resolution has been determined, either by scanning or by saving in an image-manipulation software package, it cannot be upgraded or increased to improve quality. The Tagged Image File Format TIFF is a bitmap format developed for exchanging documents between different applications and platforms. TIFF files are generally reliable for printing and cross-platform conversion, but beware, some applications will not import certain types of TIFF files. TIFF files can be saved in either Macintosh or Windows formats.