A 1954 Chinese cover in my Cold War collection nicely illustrates the messiness of stamps issued without gum:
I wasn't aware that Brazil had issued stamps without gum as recently as 1967, but I have learned that Japan did so during the Second World War, as did North Vietnam during the Vietnam War.
Bob
The ungummed stamps in Japan may have been due to a shortage of gum arabic most of which comes from Saharan Africa especially Sudan
I will not hazard an opinion regarding why Brazil's stamps were issued without gum during the years noted. I lived in Brazil from 1965-1967 and clearly remember having to affix stamps to envelopes at the post office using mucilage in a little cup with a small brush whose bristles long since had surpassed their expected lifetime. It clearly took a person with more artistic/painting ability than I possess to use this gooey substance and spent brush to affix a stamp to an envelope without creating a sticky/blotchy mess surrounding the stamp, to say nothing of risking affixing the envelope to my fingers when I picked it up to carry it to the drop slot.
What strange memories remain readily accessible in memory when so much I wish I could recall is seemingly gone forever!
re: Issues without gum
A 1954 Chinese cover in my Cold War collection nicely illustrates the messiness of stamps issued without gum:
I wasn't aware that Brazil had issued stamps without gum as recently as 1967, but I have learned that Japan did so during the Second World War, as did North Vietnam during the Vietnam War.
Bob
re: Issues without gum
The ungummed stamps in Japan may have been due to a shortage of gum arabic most of which comes from Saharan Africa especially Sudan