i need help to id this bulgarian banknotes it is thick paper not like others and with dark yellow lines and the watermarks are so clear
The yellow lines are consistent with damage from an old photo album. In the 1970-80s there were photo albums that had a sticky substance applied in diagonal stripes that held the pictures in place between the page and a cellophane cover. The adhesive leached into the note from improper storage in this type of album.