readers' letters: how many asset labels from an 8m x 9mm tz tape?

Mr TJ of Tirol writes:

How many code128 barcode 6-character asset labels can you get from a typical 8m TZ tape?

Great question.

Let's start with a fresh TZe-221 label cartridge:

I started at tj1783 on a PT7600 machine, and chose number 99 (this is the max).

It displayed 45.0 at the bottom of the display, and this is the length in mm.  I measured a label with a ruler to confirm: it was 45mm.  This indicated length did not change during the print run, implying that the lengths of these labels were not affected by character widths in the font.

Then, I chose another 99.  It finally ran out having done tj1968.  When a TZ tape runs out, you get this black and white barring effect:

If you care about not having gaps in the sequence, you have to work out which one was printed successfully last.  The barring is usually too heavy to read off the id that failed.  The easiest way is to lay the labels out in order as you cut them, as depicted, instead of allowing them to pile up and jumble up.

In total, 185 labels were printed, which answers our reader's question. At 45mm each, this implies 8.325m of usable tape in the cartridge, which compares well to the 8m it's sold as.  Give and take with the Brother label wastage engineers.