Welcome to Yin4Yang

Barcode Toolbox and Barcode CheckUp

are a collection of plug-ins to generate, check, preflight and fix
barcodes directly inside Adobe Illustrator.
However, these products are no longer available from Yin4Yang. The successor of these products is Instant Barcode from Enfocus. More information can be found on the Instant Barcode web pages.

Consultancy

Yin4Yang is a company focusing on developing products for the
graphic arts industry and the Macintosh operating system.