Friday, October 11, 2013

Logos (and Image File Types)

When working with logos, one of the main challenges (other than the design itself) is with creating and managing the many different file types and variations that would be needed for the logo image. There is no one file type that is going cover all the bases. A logo may need a collection of many different files on hand, with each being unique to the different ways that the logo is to be used. With this post we hope to briefly describe three categories of logo usage: 1) web/low resolution; 2) print/medium quality; and 3) press quality.
     Web publishing is limiting for the types of files that can be used for images. JPGs are probably most common, though GIF, PNG, and other types may also be found. Also, resolution for images is greatly diminished due to display screen limits (see web limitations). JPGs are great for photos on a web page, though for logos, they can be lacking in quality due to the compression being used. Even at the highest setting for JPG quality, pixels are degraded for quality (see JPG compression). Since logos often consist of typography and areas of high contrast, this degrading of pixel quality may be a concern. At times the logo may be improved if saved as a GIF file. The tricky thing with GIF files is that the color pallet is altered in such a way as to customize the colors used in the file to what best suits the colors used in the image. GIF files use the adjusting of the color pallet, rather than the altering of the pixels, for maintaining optimal small file sizes. GIF files also offer the ability to add animation and movement for a logo. Though it would be easy to think that these details would only be of concern for "web-designers," it is good to also note that images posted to other sites (such as social media, networking, as ads, etc.) would present similar challenges for providing optimal levels of image quality.
    "Print quality" (as it relates to printing to office/desktop type printers) represents in improvement over the low resolution of web images. Most inkjet and laser printers output in the range of 300-600 DPI (dots per inch) which is considerably higher than screen resolutions of web published images. Aside from resolution, another consideration is with how the logo is to be used within different programs for creating documents. Most programs allow for the placement of images though this is limited to specific types of image files. Generally (for reasons of quality and for compatibility with programs) logos as TIF files will work fine. There are some instances though where a totally different type of file may be better (for sake of image quality). TIF files (as with JPG, GIF, and many others) are bitmap images. The alternative to this would be vector images. EPS image files, for example, allow for vector defined images (see vectors and bitmaps). Though EPS files are very common for logos (and are very versatile as a file type), there may be some challenges. One potential problem may be compatibility with the programs used for creating documents, and maybe too, the printers used for printing documents.
     "Press quality" represents an even higher level of quality for logo images. In this instance logo files are being sent to individual printing companies with requirements specific to their equipment and production processes. Though the term "press" may imply to just printing with ink onto paper, it is not limited to just that. Other examples, to name a few, would be companies whose specialty is with digital printing (toner on paper), sign printing (cut vinyl signs, vehicle signage, billboards, etc.), and specialty/screen printing (tee shirts, mugs, etc.).
     Sometimes a TIF file (at an appropriate level of resolution) may be all that is needed. Other times a vector image (such as EPS) is what is required. For example, for large printings where dimensions are measured in feet rather than inches (signs, posters, etc.), resolution dependent images may be inadequate. Vector defined images can be enlarged to whatever size is needed without loss of quality.
     For some printing processes (such as screen printing, vinyl cut signs, etc.) the logo's design may actually need to be simplified. A less detailed version of the logo's design may be needed. For example, if gradients are used in the logo image this may need to be replaced with areas of only solid colors. (Logos with photographic components or ones that include very fine detail can be especially challenging.) Though it may seem extreme to change a logo's design to this extent, depending on how it is to print, this is what may be needed. A simplified version of a logo's design does not necessarily imply an image of lesser quality. On the other hand, it could be said that quality is increased by the tailoring of the logo image (simplifying) to better match the process being used for printing.
    Another consideration is with color. For a logo consisting of multiple colors the colors may be defined in several different ways. Where RGB (red, green, blue) defined colors (such as within a TIF file) may be good for the home/office printer, it is not adequate for sending to a print shop for printing in "process" four colors (CMYK) with inks or toners of the colors cyan, magenta, yellow, and black (see elements of color). Aside from using process CMYK colors, at times printing is done with Pantone colors which is with inks that are formulated to specific colors (per Pantone matching swatches). In all instances, the logo image file would need to "color separate" into the specific colors needed for the printing process being used.
     When creating and deciding on a logo's design, it is good to keep in mind all the various ways that the logo may need to print. An overly detailed or colorful logo, may also, at times, need to be expressed in much simpler terms.
     Having an appropriate collection of logo files on hand ultimately is the goal. Depending on who would be using these files, it is often helpful to also prepare a document with guidelines relating to the logo's usage and the merits of the different files available. Hopefully this post can serve as an introduction to some of what is involved with creating an effective collection of logo files specific to the different ways that the logo may be used.

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