The BSG format is associated with Fontasy Grafik, a graphics design software program which has been discontinued for a long time. Such files are no longer supported by their developer, so for opening them it is probably best to convert to a more popular format.
The quick and simple way to handle your files is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch conversions. As you will soon realize, reaConverter will help you avoid spending countless hours trying to figure out how to convert multiple BSG files as once.
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