I don't know when the slick covers started to appear. I know they were around by the 1960's. In the 1990's they began to be replaced by non-slick covers. Some of you will agree with me that the newer, non-slick covers are much more unpleasant to the touch, and many of you, perhaps most of you, will have no earthly idea what I'm talking about.
And so, for those of you who have no idea what I'm talking about, I'm going to give you some examples, so that you can go to your local library or used-book store and put your own fingertips on these items: Grand Street vol 3, #4, 1984, #37 & 38, 1991, and #46, 1993, are all slick; #55, 1996, and #69, 1999, are non-slick.
The 1999 paperback re-print of Cambridge University Press' 3-volume edition of Steven Runciman's History of the Crusades has slick covers.
Cormac McCarthy paperbacks published by Vintage: the 1st Vintage International editions of All the Pretty Horses, The Crossing and Cities of the Plain have slick covers. The 1st Vintage International editions of Outer Dark and Child of God have non-slick covers. The Vintage Movie tie-In editions of No Country For Old Men and The Road have slick covers.
The 1993 Quality Paperback Book Club volume containing The Orchard Keeper, Suttree and Blood Meridian by McCarthy has a slick cover.
The cover of the 2006 30th Anniversary edition paperback of The Selfish Gene by Richard Dawkins, published by Oxford University Press, is slick on the back and spine and non-slick on the front.
1988 Harcourt, Brace 3rd edition of the AIA Guide to New York City, slick; 2010 Oxford 5th edition, non-slick.
Dtv (Deutscher Taschenbuch Verlag) was all slick until the late 1980's when it began to convert; by the late 1990's, or earlier, it was all non-slick.
clasicos castilia of the 1980 and 90's were slick. Back then their pages were sewn in signatures instead of glued to the spines, which is unusually high-quality for paperbacks. I don't know if they're still slick or sewn in, I hope they're both.
Somebody somewhere must think that the new non-slick covers are better. I certainly don't, and I know that at least some other people also are strongly in favor of slick. Non-slick covers are intensely unpleasant to my touch. I've gone so far as to completely cover the non-slick covers of some books with scotch tape. That results in a feel similar to slick covers.
Maybe with your support, this long international nightmare will finally end.