Starting with bulletin #152, the format changed. A single bulletin now was printed in 4 languages, and a colored background was added to the central portion of the bulletin. The bulletin orientation also changed from portrait to landscape. This design was used through bulletin #286. One thing to note, however, is that the numbers are no longer strictly integers, as several a and b suffixes were added over the years.
Bulletin #287 started the use of a new format. The paper was cut approximately in half, and the bulletin was now printed on both sides, with the front having only a picture of the stamps, and the information being printed on the back. This format was discontinued after only a brief usage, with bulletin #308 being the last one printed in this format.
The next format, shown here on the right, is the last one I have seen used. Once again, these were single sided bulletins, with the color now restricted to the title. The stamps and descriptions are printed in a single color, but it is no longer limited to just the black ink used previously. I believe each bulletin was printed in only a single color, since I have yet to see multiple color versions of a single bulletin, but there are ones printed in black, brown, blue, and green. This last format was printed in strips of 3 consecutively numbered bulletins, I have several uncut strips of 3 in my collection. I have shown one below. Of these, I am once again missing a few, #401, 437, 442, and 460. The last bulletin I have is number #498, the 40th anniversary souvenir sheet issued in 1988. If anyone knows of ones issued later, please let me know.