Table of Contents
Vector graphics are often described as “can be scaled indefinitely without degrading”. While this assertion holds true in many cases, it is not true when the dimension is small and the resolution of the drawing surface is low. All drawings are eventually converted to pixels, and the size of pixel imposes a severe restriction on barcode quality.
This release has taken the pixelization into count when the font was designed. As long as you follow the instruction below you should be able to create high quality barcodes, even at small dimensions on low resolution printers.
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.
Table 3.1. Font Selection Based on Barcode Type
Barcode Type | Total Height | Font to Use | Encode Function |
---|---|---|---|
DataBar14 | 34X | MRV DataBar 34X | DataBar |
DataBar Truncated | 13X | MRV DataBar 13X | DataBar14 |
DataBar Limited | 13X | MRV DataBar 13X | DataBarLimited |
DataBar Stacked | 13X | MRV DataBar 13X | DataBarStacked |
DataBar Stacked Omnidirectional | 34X | MRV DataBar 34X | DataBarStackedOmni |
DataBar Expanded | 34X | MRV DataBar 34X | DataBarExpanded |
DataBar Expanded Stacked | >=71X | MRV DataBar 34X | DataBarExpanded |
Code128 | 34X | MRV DataBar 34X | Code128_Uni |
GS1-128 | 34X | MRV DataBar 34X | EAN128_Uni |
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
.
Table 3.2. X Dimensions List
Font Size | X Dimension | Font Size | X Dimension | ||
---|---|---|---|---|---|
6 pt^{[a]} | 5 mils | 0.013 cm | 28 pt^{[b]} | 23 mils | 0.059 cm |
8 pt^{[b]} | 7 mils | 0.017 cm | 30 pt^{[a]} | 25 mils | 0.063 cm |
10 pt | 8 mils | 0.021 cm | 32 pt^{[b]} | 26 mils | 0.065 cm |
12 pt^{[a]} ^{[b]} | 10 mils | 0.025 cm | 34 pt | 28 mils | 0.071 cm |
14 pt | 12 mils | 0.029 cm | 36 pt^{[a]} ^{[b]} | 30 mils | 0.076 cm |
16 pt^{[b]} | 13 mils | 0.034 cm | 38 pt | 31 mils | 0.080 cm |
18 pt^{[a]} | 15 mils | 0.038 cm | 40 pt^{[b]} | 33 mils | 0.084 cm |
20 pt^{[b]} | 17 mils | 0.042 cm | 42 pt^{[a]} | 35 mils | 0.088 cm |
22 pt | 18 mils | 0.046 cm | 44 pt^{[b]} | 36 mils | 0.092 cm |
24 pt^{[a]} ^{[b]} | 20 mils | 0.050 cm | 46 pt | 38 mils | 0.097 cm |
26 pt | 22 mils | 0.055 cm | 48 pt^{[a]} ^{[b]} | 40 mils | 0.101 cm |
^{[a] } Optimal size for 203-dpi printers ^{[b] } Optimal size for 300-dpi printers |
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:
Table 3.3. X Dimensions List for Screen Fonts
Font Size | X Dimension | Font Size | X Dimension | ||
---|---|---|---|---|---|
12 pt | 10 mils | 0.025 cm | 24 pt | 20 mils | 0.050 cm |
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>
.
^{[3] }1 mil = 1/1000 inch.
^{[4] }Note that 18 pt is not an optimal size for a 300-dpi printer. On the other side, it is an optimal size for a 203-dpi printer.