Universal Product Codes
When a UPC is required, high standards are strictly enforced. In some cases, a non-readable UPC can cost product owners fines, concessions to retailers, and worse yet, product pulled off shelves never to be sold. Therefore, it is important to understand what is involved in the creation of a quality, readable UPC.
ANATOMY OF A UPC
1. Number System Character - the first number of the UPC, this number assigned by the Uniform Code Council simply indicates the number system that is to follow.
2. Manufacturer Identification Number - a unique 5 digit number assigned by the Uniform Code Council.
3. Item Number - a 5 digit number assigned and controlled by the product owner.
4. Check Character - the last number of the UPC, it is used to verify the accuracy of the entire UPC.
IMPORTANT UPC CHARACTERISTICS
1. Size - the nominal size is 1.469" wide x 1.02" high including the number system and check characters. The minimum recommended size, 80% of the nominal size, is 1.175" wide x .816" high. The maximum recommended size, 200% of the nominal size, is 2.938" wide x 2.04" high. In general, larger UPC's scan better. Size may vary depending on package design and printing conditions.
2. Contrast - the level of contrast between bars and spaces helps determine the readability of a bar code. Although many color combinations may be used, the most reliable combination is black bars with white spaces. If that combination is not feasible, an alternative combination of dark bars with light spaces is always recommended. Since the scanner uses infrared light to read the bar code, the color red cannot be scanned and therefore should not be used as any part of the UPC.
3. Quiet Zone - the required area to the left and right of the bar code free of all printing, this area prepares the scanner for the bar code that is to follow. Since bar codes can be read from either direction, quiet zones are required on both ends.
4. Bar/Space Pattern - every number has a unique pattern of bars and spaces of varying widths. Accurate printing of these patterns and their widths is essential.
1. Location - The UPC should be located in the center of the package's "natural bottom". This is determined by considering the design of the container as well as the orientation of the package graphics.
2. Show-Through - Show-through can occur with transparent or translucent packages when the product is seen through the spaces of a bar code. This can yield a bar code unreadable and can be avoided by overlaying an opaque white background with dark bars.
3. Truncation - Truncation is decreasing the height but not the width of a bar code. Although not recommended, truncation is sometimes necessary. Manufactures should try to reduce the bar code within the established limits before cutting off the top of the bar code through truncation.
4. Printing Methods - Different printing methods effect the image quality of a UPC in different ways and, therefore, steps must be taken to counteract any negative effects. For example, in silk screening, the occurrence of ink spread must be calculated and bar width reduction must be incorporated into the film master. Ink spread can also decrease the flexibility of size reduction of a bar code. If a bar code is reduced too much, an attempt to silk screen it will blur the bars together. This is one of the reasons why it is recommended to keep the bar code within the minimum of 80% of the nominal size.
The printing methods also affect the position of the bar code. With any method that might involve ink spread, it is best to position the bar code on its side so that the bars run in the same direction as the ink flows during the printing process. This insures that any blurring will affect bar length rather than bar width, which is more crucial to readability.