I have lived in Japan during many different periods in my life, but the only time when I or my family bought pencils was during the years 1979-1982. I still have some left. I can state with confidence that the most important principle for budding stationery aficionados is Never Throw Anything Away.
Even after thirty years, it is hard to convince anyone that they are indeed that old, partly because the imprint has hardly changed and partly because the lacquered surface has not degraded one bit during all that time. You may have your preferences and prejudices, but the truth is no one does pencil coats quite like the Japanese.
Because I was so attached to them, and because they looked so good, I thought of them very highly for a long time. It was only after I tried other “flagship”-grade pencils during the past few years that I realized the 9800 was meant to be and indeed performed like an inexpensive office/school pencil. The higher-grade Uni (and even the Hi-Uni) was already available at that time, which leaves me to wonder: could my parents not afford the Uni? My father was partial to stationery products and especially to his Parker pens even then; did he think pencils were not worth the investment? Or maybe the 9800s were deemed good enough for children? Anyway it took me a long time to get to the Hi-Uni, and I have to confess that even now I find its color and feel quite unfamiliar. (Here is an interesting article on the history of the Uni.)
I haven’t bought a modern 9800 since then so I can only guess based on the pictures I see on other blogs, but there are two differences in the imprint that I can point out.
Some of the 9800s I have have “Patented” imprinted on them; I think they are older than the “Matured” pencils. (The pencil box also states “Patented”. ) Also, on the backside of the “patented” pencils, the patent number is inscribed along with the JIS mark. The “Matured” pencils have “General Writing” on them. Maybe, as Gunther says, the patent expired in the meantime and they were in the process of transition?
The JIS mark is another interesting point. This mark is the seal of approval that the government bestows on products that have met certain industrial standards. We had the same kind of quality-certification system in Korea too, called the KS mark, and I associate these symbols mainly with the 70’s and 80’s, when many companies were trying hard to bring themselves up to international standards of manufacturing and a government-issued seal of approval helped to advertise the superior quality of their products. Now that firms are successful enough on their own, I find that many are phasing out the symbols from their packaging. I can’t find a JIS mark on any of the modern Mitsubishis or Tombows I have, although I do see it on the Pentel Black Polymer. If you do find one on a recently produced pencil, I’d be interested to know.
PS – It’s funny that Mitsubishi uses “Color” and “Colour” interchangeably on the imprints. Also it says “Made By Elaborate Process” on the back side of the 9000 – a charming piece of Japlish ;)