1 00:00:00,160 --> 00:00:03,600 Speaker 1: Jack Threads is the online shopping destination for dudes. Everything 2 00:00:03,600 --> 00:00:06,520 Speaker 1: on the side is up to off, all styles are curated, 3 00:00:06,559 --> 00:00:09,400 Speaker 1: so buyer's remorse just doesn't happen. What's more is if 4 00:00:09,400 --> 00:00:11,680 Speaker 1: you were brain stuff, you can skip the membership wait 5 00:00:11,720 --> 00:00:14,320 Speaker 1: list and get instant access at jack threads dot com 6 00:00:14,360 --> 00:00:18,439 Speaker 1: slash stuff. Welcome to Brainstuff from house stuff works dot 7 00:00:18,440 --> 00:00:29,800 Speaker 1: com where smart happens. I am Marshall Brain with today's question, 8 00:00:30,200 --> 00:00:34,320 Speaker 1: what exactly is a blueprint? If you've ever watched a 9 00:00:34,400 --> 00:00:36,839 Speaker 1: house being built, or if you've ever had an addition 10 00:00:36,920 --> 00:00:40,040 Speaker 1: put onto an existing house, you know that the standard 11 00:00:40,080 --> 00:00:43,240 Speaker 1: method of communication is a big piece of paper called 12 00:00:43,280 --> 00:00:48,400 Speaker 1: a blueprint. Blueprinting is a way to copy large architectural 13 00:00:48,479 --> 00:00:52,360 Speaker 1: and construction drawings. A blueprint used to consist of white 14 00:00:52,400 --> 00:00:56,720 Speaker 1: lines on a blue background. More recent processes use blue 15 00:00:56,760 --> 00:01:00,680 Speaker 1: lines on a white background. The term blueprint is usually 16 00:01:00,760 --> 00:01:05,000 Speaker 1: used to describe two printing methods, the blueprint and the 17 00:01:05,160 --> 00:01:09,600 Speaker 1: diaze type. Blueprinting is the older method, invented in eighteen 18 00:01:09,840 --> 00:01:14,200 Speaker 1: forty two. The drawing to be copied drawn on translucent 19 00:01:14,280 --> 00:01:18,080 Speaker 1: paper is placed against paper sensitized with a mixture of 20 00:01:18,200 --> 00:01:24,039 Speaker 1: ferric ammonium citrate and potassium ferricyanide. The sensitized paper is 21 00:01:24,080 --> 00:01:27,640 Speaker 1: then exposed a light where the areas of the sensitized 22 00:01:27,680 --> 00:01:31,120 Speaker 1: paper are not obscured by the drawing. The light makes 23 00:01:31,160 --> 00:01:35,240 Speaker 1: the two chemicals react to form blue. The exposed paper 24 00:01:35,319 --> 00:01:38,959 Speaker 1: is then washed in water. This produces a negative image, 25 00:01:39,000 --> 00:01:43,120 Speaker 1: with the drawing appearing in white against a dark blue background. 26 00:01:43,640 --> 00:01:47,800 Speaker 1: In the diaze type method, the paper is light sensitized 27 00:01:47,840 --> 00:01:51,840 Speaker 1: with a mixture of diazonium salt used in the manufacture 28 00:01:51,840 --> 00:01:55,440 Speaker 1: of dyes, a reactant, and an acid that keeps the 29 00:01:55,520 --> 00:01:58,920 Speaker 1: salt and the reactant from reacting with each other. The 30 00:01:59,000 --> 00:02:03,120 Speaker 1: semi transparent original is placed on top of this sensitized paper, 31 00:02:03,520 --> 00:02:06,480 Speaker 1: and a copy of the same size as the original 32 00:02:06,640 --> 00:02:11,800 Speaker 1: is made by direct contact. Light destroys the salt. Ammonia 33 00:02:12,320 --> 00:02:16,040 Speaker 1: is used to develop after the exposure. It neutralizes the 34 00:02:16,120 --> 00:02:19,480 Speaker 1: acid and allows the remaining salt to combine with the 35 00:02:19,520 --> 00:02:22,760 Speaker 1: reactant to form the blue dye. The chemicals on the 36 00:02:22,800 --> 00:02:26,760 Speaker 1: paper acquire color only in the areas not exposed to 37 00:02:26,800 --> 00:02:31,240 Speaker 1: the light. This diaze type method produces dark lines on 38 00:02:31,280 --> 00:02:35,000 Speaker 1: a white background, and it's a popular method used today 39 00:02:35,040 --> 00:02:38,840 Speaker 1: for reproduction of large format drawings. The reason people still 40 00:02:39,000 --> 00:02:43,560 Speaker 1: use blueprints is because it's an inexpensive process, but large 41 00:02:43,639 --> 00:02:47,120 Speaker 1: format printers and copiers are getting cheaper and cheaper, and 42 00:02:47,160 --> 00:02:52,120 Speaker 1: they'll eventually replace blueprints completely. For more on this and 43 00:02:52,160 --> 00:02:59,000 Speaker 1: thousands of other topics, is it how staff works dot com. 44 00:02:59,040 --> 00:03:02,320 Speaker 1: Audible dot com is the leading provider of downloadable digital 45 00:03:02,360 --> 00:03:06,040 Speaker 1: audio books and spoken word entertainment. Audible has over one 46 00:03:06,120 --> 00:03:08,960 Speaker 1: hundred thousand titles to choose from to be downloaded to 47 00:03:09,000 --> 00:03:12,600 Speaker 1: your iPod or MP three player. Go to audible podcast 48 00:03:12,639 --> 00:03:15,000 Speaker 1: dot com slash brain stuff to get a free audio 49 00:03:15,040 --> 00:03:17,440 Speaker 1: book download of your choice when you sign up today.