Bar code fonts do not modify the data in any way however you almost
certainly will need to change the data before you will be able to use
a bar code font with it. Code 39 bar code fonts require that you put
an asterisk both before and after the actual data that you want to
encode in the bar code. If the asterisks are not there then the bar
codes will not read. Basically they act as Start and Stop codes to
indicate the beginning and end of a bar code.
In general, bar code fonts produce extremely poor quality bar codes
that can be difficult to read and they are also usually not very
"device independent" meaning that different printers will output them
differently and you might get readable bar codes when you print to one
printer and then get unreadable bar codes when you print to a
different printer.
If you want perfectly readable bar codes no matter what printer you
print to, then you are much better off using a good quality bar code
ActiveX control that produces Windows metafile (device independent)
graphic images of bar codes.
The absolute best one on the market is from TAL Technologies. You can
download a demo of their control from the following web page:
http://www.taltech.com/products/activex_barcodes.html
The demo version of the ActiveX control comes with a sample Access
database that demonstrates how to use it to print bar codes in Access
reports. Basically you drop the control onto your report exactly the
same way you would put a textbox on the report and then "bind" the
control to a "data source" so that the bar code data is linked
directly to the control. When you print your report, you get perfect
bar codes encoding your data. You also do not have to modify your data
in any way whatsoever.
