If you have a hard drive attached to your ST, you might want to transfer files bigger than what can fit on a single floppy. You can achieve this using ARJ compression software, available for PC here and ST here.
Once you have the software downloaded and extracted, use your PC split the large file into 720KB (or, if your drive supports it, 1440KB) chunks:
ARJ32 a -jm -r -v720 arc.arj largefile.jpg
You’ll get multiple files, starting with arc.arj, followed by arc.a01, arc.a02 etc.
Use floppies to shuffle the files across to your ST one-by-one.
Once you’ve moved all the files across, use UnARJ to extract the original large file. The easiest way is to drag arc.arj onto unarj.ttp, after which UnARJ will work its magic automatically:

In older versions of TOS, drag-and-drop won’t work - you’ll need to double click unarj.ttp and type in the archive source path:

That’s all there is to it! Easy when you know how.
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