Banknotes obtained from the primary market (not collectors).
Interesting, cincturist alterations from the communist period (for tourists) of the occupation-era, invalidated after the war, 100-zloty bills into 1000-zloty bills, by pasting one zero in all, digital denomination markings, without replacing the inscriptions and date.
Trimmed to a smaller format, presumably to resemble the then-achieving issue.
A video of similar alterations on YouTube: How foreign tourists were cheated on currency in communist Poland... and not only tourists