Unless special condition dictates otherwise, in general you should choose from the two fonts: MRV DataBar 13X and MRV DataBar 34X. The former produces barcodes at 13X (i.e. the bar height is 13 times the X dimension) and the second at 34X. In order for the barcode to read omnidirectionally, you should always use MRV DataBar 34X to creating omnidrectional capable barcodes, such as DataBar and DataBar Expanded.

Because GS1 DataBar Expanded Stacked may have multiple rows, the total height depends on the number of rows: height = 34X + (number_of_rows)*37X

Although font characters scale linearly and print any sizes required, not all sizes will produce best quality barcodes. The reason is that printers can only address individual pixels instead of a length specified in inches or centimeters. For example, a printer dot measures 3.33 mils ^[3] on a 300-dpi printer. Certainly you can not print a size smaller than 3.33 mils. And you can not consistently print a length of 5 mils, because this printer either prints 3.33 mils, or 6.66 mils in this case. We call a font size optimal when the dots produced always remain constant. This is vital to small size barcodes where the barcode quality largely depends on the constant width of elements. On the other side, this is usually not a problem when X dimension is big enough (such as 15 and 20 mils).

The optimal sizes for DataBar fonts are integral times of 4 on a 300-dpi printer, integral times of 2 on a 600-dpi printer and integral times of 6 on a 203-dpi printer.

The following table lists all nominal X dimensions and font size correspondence for fonts MRV DataBar 13X, MRV DataBar 30X and MRV DataBar 34X.

The characteristics for screen fonts (MRV DataBar 13X 96dpi) and (MRV DataBar 34X 96 dpi) are explained later in the chapter.

For example, supposing that X-dimension required is 15 mils, from Table 3.2, “X Dimensions List”, the optimal size is 18 points on a 600-dpi printer. ^[4]

In order to create a stacked barcode, the gap between two adjacent lines must be zero. Unfortunately, not all applications handle line gaps correctly, including some well-known programs, such as Adobe InDesign and Microsoft Viso.

When creating DataBar Stacked Ominidirectional and DataBar Expanded Stacked barcodes, the two rows overlap in those applications, as illustrated below.

Some applications allow you to adjust line height. Others do not offer options to adjust line height. For the latter case you may attempt to replace the font with MRV DataBar EM and to see if the problem is solved. This font was design to have its character height match the point size.

However, the barcode created using this font is only the half size of the one created using other fonts. In order to match the size, you need to increase the font size to twice the original size. For example, to match a barcode created under 12 points using MRV DataBar 34X, format with 24 points with MRV DataBar EM.

Formatted with MRV DataBar 34X 12 points, line height at 100% (Microsoft Visio)	Formatted with MRV DataBar EM 24 points, line height at 100% (Microsoft Visio)

For workaround in Adobe Illustrator, see http://www.barcodeschool.com/2009/02/creating-a-stacked-databar-barcode-in-adobe-ilustrator/.

Two complementary fonts, MRV DataBar 13X 96dpi and MRV DataBar 34X 96 dpi are supplied for “on-screen” use. Some painting programs rasterize text under screen resolution. Some graphics APIs do not allow you to specify a resolution value when converting text to bitmaps.

Barcodes displayed on screen with the two screen fonts at designated font sizes are “screen copyable”. You can use this method to quickly create a bitmap image for your web site while retaining high barcode quality. You can also use the fonts in programs such as Microsoft Paint.

Because the size of a screen pixel is relatively large (10 mils), the available selection of X dimensions is limited. See the table below for the font size list:

Fonts are easy to use and portable among systems. On the other side, font characters scale in both directions. That means it is impossible to get both sizes match exactly in some cases. The bar height always scales up and down at the same time X-dimension scales up and down.

Considering the potential customization requests to meet special needs, Morovia offers custom font services at reasonable cost. For example, we can create a font that meets both bar height and X dimension requirements accurately. Note that this service is offered only to customers who already purchased a license of the font, and the license term of the modified font follows the product to be replaced. If you have such needs, contact us at <support@morovia.com>.