Infinite Sets. If you continue to study this subject you will find discussions about infinite sets, and the idea of different sizes of infinity. That subject has special names like Aleph-null (how many Natural Numbers), Aleph-one and so on, which are used to measure the sizes of sets.
For decades, glossy paper, the type used in magazines, was made using a white clay called kaolin (named after the Chinese region Kao-Ling where it was mined to produce porcelain).
Original: The first copy of Playboy magazine featuring Marilyn Monroe as centerfold is to go under the hammer Thursday in Los Angeles. A world away from its modern, glossy successor, this copy boasts it is the first full color magazine but is in black, white, grey and a touch of red.