Artwork can be provided in many ways but the best output will always come from ‘vector’ files. This is 'line' artwork created in Illustrator or CorelDraw that can be used for color separations and enlarged without reducing the quality. Any part of the artwork can be moved around & changed without any quality being lost. Fig. 1 shows the clarity of a vector file. Vector artwork can be saved as an 'eps' file which is a generic platform enabling the file to be opened in a variety of programs. Illustrator can be saved as 'ai' and CorelDraw as 'cdr', but they can both be saved as 'eps'.
Any artwork supplied as 'jpg', 'gif', ‘png’, 'tif' or 'bmp' are bitmap files (eg. photographs). These are difficult to separate depending on quality and most are of a low dpi (dots per inch), which means the edges of the artwork has a ragged appearance when magnified. See Fig. 2. Bitmap files will mostly print as four color process but to enable perfect color separations, they should be submitted at actual size and with a high dpi (300+). Anything less will produce less satisfactory results. Most images from the internet have a dpi of 72, and will never produce good printing results. Indesign and PDF files are also accepted.
Low quality bitmaps can be recreated for a charge, but the client should be made aware that any font styles may not be replicated exactly, unless the client can supply a font file (ttf). Art files that are submitted as vector will not incur art charges, but any bitmap files submitted may be charged at an hourly rate to be recreated or converted for print ouput.