In the years from 1975 through 2000, architectural drafting and reproduction media changed profoundly. As student, intern, and architect, I witnessed the revolution. The following comes from memory, various texts, and antiques in my bottom desk drawer.
1975 Vellum (paper, not calf hide) was standard with ink and pencil. Equipment consisted of: high drafting table and stool; adjustable lamp (fluorescent, incandescent, or both); T-square or parallel bar; scales; triangles; curves; lettering guides and templates; compass sets; tape; technical pens; lead holders; erasers; and such exotica as Pounce. As a student (Syracuse University School of Architecture), studio standards were: high drafting boards of oak (old) or gray steel (new), unpadded, backless, drafting stools, and parallel bars. Perhaps a quarter of the students used T-squares.
For construction drawings, pencil on vellum was usual, sometimes ink because it printed better. Mylar sheets were newly available, with a "frosted" surface to take ink. These printed best - because of Mylar's transparency - but were expensive. Colored pencils and pastels were used for renderings, though colored markers were most popular, and ink wash - in the Beaux Arts tradition - lingered. Reproduction was by Diazo process - using ammonia - so prints had a potent perfume. Blueprints were archaic - bluelines read better. Sepia prints were used for reproducibles (to spare original drawings from the print machine). Blacklines were for presentation, sometimes colored by marker or pencil.
1980 As an intern (Dallas, Texas), standards for a professional architect's office were: low drafting board (metal-legged or classic, slab door on sawhorses); secretarial swivel chair (arms were a perk); drafting lamp; and parallel bar. (Old-fashioned firms were just switching from the T-square). Drafting was changing from pencil-on-vellum to ink-on-Mylar. Most firms had Diazo. The last professional draftsmen were nearing retirement. In the '80s most states changed licensing laws to require college degrees. (Until then, in New York State, for example, one could pass the licensing exam after working 13 years - an apprenticeship which produced incompetents like Frank Lloyd Wright.)
Mid '80s Rapid change. To improve drawings and reproduction, new techniques were tried. Drafting machines (existing in the '60s) were briefly popular. Pinbar drafting was introduced. Various drafting aids were adopted. Large format photocopies became available - though expensive - used to create reproducibles from fragile drawings, where sepia printing would be illegible or too damaging.
1990s Computer Aided Drafting - CAD - became more and more common. Early cumbersome network systems (the one at GM in 1968 is enormous ), were replaced by the mid '90s with entirely PC based CAD. Diazo printing declined as CAD plots grew common.
2000 CAD is universal. Allied engineering fields (structural, mechanical, and electrical) now demand CAD base drawings. Few architects draw by hand, few even have drafting boards. T-squares have virtually disappeared. Commercial bluelines are used for bidding or construction sets; in-office sets and presentations are now normally CAD plots. Sepia and blackline prints are rare and blueprints nostalgic. Renderings may be any media, but markers are passé, while 3-D CAD virtual walk-throughs are progressive.
DEAD MEDIA: MATERIALS EQUIPMENT AND METHODS Drafting Board Pre 1975, these were standing height and wood (oak) or metal DYING (steel) with 4 legs, a stretcher/footrest, and a right-hand drawer for drafting tools and the draftsman's (or -woman's) coffee cup - which collected eraser crumbs. By 1980, boards were chair height and metal (often tubular). Drafting surfaces were often covered with stiff, waxy, gridded paper or soft vinyl board cover (both either pale green or white). A popular accessory was a roller bar (or "bellybar"), an aluminum tube at the bottom of the board. As the drawing was slid closer to the draftsman, extra paper curled in the protective tube. (As did eraser crumbs and spilled Coke. It came with a round cleaning brush.) Essential through the 1980s, the drafting board is now disappearing from architecture offices. Drafting Stool Old draftsmen sat on tall, hard, oak, backless stools. Since the DEAD '70s, this stool started to roll and swivel, grew a back and padding and shorter… and disappeared. Like its partner the drafting board. T-Square This T shaped tool was usually hardwood (often beech) with DEAD clear plastic edges. It slid up and down the - hopefully - straight edge of the drafting board to draw parallel horizontal lines… if the draftsman was alert. Otherwise, drawings got a strange splayed look as it slipped. Listed as "essential drafting equipment" in 1968  it has virtually disappeared today. Manufacturers (circa 1970-80s) included Dietzgen with its "Globe" # 12077-24. Parallel Bar This replaced the T-square because it was less temperamental. A DYING strip of wood or fiberglass (?) with clear plastic edges, it ran along wires at each side of the drafting board, attached at the board's corners, with a tension spring and lock at the top. A broken wire necessitated feeding of wire through the length of the bar. Sizes varied from tiny to the more common just longer than 42" drawing width. It was not mentioned as existing in 1968 . Manufacturers included Mayline and Dietzgen. Drafting Machine A movable arm with an L shaped gizmo, marked in inches, which DEAD pivoted by measured degrees to allow drawing perpendicular lines at any angle. But the L was too small to draw long lines and the arm was both too stiff -hard to adjust correctly - and too flimsy -always wandering out of alignment. Basic Graphics  has an illustration. The parallel bar was much easier to use. Pin-Bar Another good idea which was a pain to use. Drawings were made EXTINCT on clear Mylar sheets, superimposed on each other through using the pinbar - a metal strip with raised buttons to fit holes at the top of the sheets. On one level would be drawn, say, walls. On another, doors. On another, a ceiling grid. By layering walls/doors or walls/ceiling the architect could print either a floor plan or a reflected ceiling plan. This is exactly the organizational theory behind CAD drawings… without the irritating pinbar, which, like sweater buttons, was always one button off somehow. An additional irritant was the flat bed printer it required (see below) since this mess would not feed through a Diazo printer. Triangles Wooden versions were replaced by clear plastics. 30/60 and 45 ALIVE & DEAD degrees are standard. Plastic triangles come in varied colors, including clear, yellow, and shocking pink, with straight or beveled edges (for ink). Adjustable triangles ("protractor angles" ) have two halves and protractor-like measure/lock which allows them to change angle. Now rare. Curves French curves are like plastic triangles (but not triangular), ALIVE & DEAD to trace curves. They are common, but their exotic brethren, adjustable and flexible curves, are now rare. The adjustable curve had a spring tension controlled "curve" adjustable "from 6 ½" to infinity." One manufacturer was Acu-Arc. Flexible curves were like Gumby - wire embedded in rubbery plastic - twist as desired. One manufacturer was Morilla with its "unique flexicurve." Templates Plastic templates create uniform symbols like lettering, toilets, DYING furniture, arrows, circles, etc. Their use has diminished with the move away from hand drafting. It was necessary to add wads of tape on the back to keep ink from wicking underneath. Compass and Divider Shiny, beautifully finished, fine precision tools, compasses DYING and dividers are now seldom used. As of 1968 , sets included small and large bow compasses, perhaps a beam compass (for larger circles), a pair of dividers, and a ruling pen (now obsolete), or, later, a technical pen adapter. Manufacturers included: Dietzgen and Staetdler/Mars. Measuring Tools Protractors establish angles, but rarely nowadays, although ALIVE, DYING, DEAD standard in 1968 . Architect's and Engineer's scales seem eternal (metric may change the former), but gadgets like the "Rolling Ruler" die out. This was a clear plastic ruler - for horizontal measurement - with a roller to measure vertical distances. Made in Taiwan for MSR Imports Inc., the model I inherited looks unused.
Hand Lettering No hand drafting, no hand lettering. But in 1968, Basic Graphics DEAD, ALAS  devoted its first chapter to the subject. Architects preferred a loose, free hand style with thin vertical strokes and thick horizontals . Engineers preferred more mechanical styles  and used aids like the Ames Lettering Guide or Braddock lettering triangle to draw guidelines. Mechanical Lettering A Leroy Lettering Guide consisted of laminate strips with ALIVE & DEAD incised letters in which a metal scribe traveled - using metal arms, this controlled a pen tip resting on the drawing. In 1968  a K & E Photo-draft system, something like a huge typewriter/camera, did mechanical drawing, symbols, and letters. In the '80s Croy machines were popular. These had a spinning dial displaying type etc. and produced clear tape with printed letters ready to stick on drawings. "Stickybacks" were photocopies on clear, adhesive sheets used to transfer schedules or details onto sheets. All modern CAD lettering is, of course, mechanical. Pens A ruling pen was standard for ink drafting until approx. the 1970s ALIVE & DYING and a normal part of a compass set. It consisted of a handle with & DEAD two prongs held by an adjustable screw which controlled the gap between them and the thickness of the ink line. Ink was held in the narrow gap. The ruling pen required an art and magic lost to architects of my generation; I made blots, not lines. In the 1968 edition of Basic Graphics , the author shows extinct drawing pens by Barch-Payzant, Edco, and Leroy. With the pen came pen-wipers, pen-holders, ink bottles, and ink bottle-holders. By 1975, all were replaced by the technical pen with refillable cartridges and an tip which determined line thickness. Tips were tiny tubes in which a hair-like wire acted as a wick for ink. Line quality was more controlled and exact than by ruling pen, but tips wore unevenly and had to be replaced. And ink dried instantly, requiring frequent and heroic cleaning. (Many a wire went down a drain…) Manufacturers included Staedtler/Mars and Rotring. Technical pens are being replaced by disposable pens (no cleaning!) like Staedtler's "pigment liner." Pencils The first drafting pencils were wooden ones with soft lead like HB, AILING medium like H or F, harder like 2H, or extra hard like 4H and 6H. These were largely replaced by lead holders, but mentioned in 1975 . One manufacturer is A.W. Faber Castell. Lead Holders/Lead Separate leads (as thick as in a pencil) were held in plastic or DYING metal holders, like the aluminum "Koh-I-Noor" technograph. Standard in the 1970s (called "traditional" in 1975 ), they are being replaced by today's small diameter leads. Manufacturers included: Staetdler/Mars "lumograph" and Berol Turquoise Eagle. Extinct "plastic" leads were for use on Mylar; fragile, constantly snapping leads that gave poor, crumbly, pale lines which did not print. In approx. 1998 these leads were in the "discontinued" bin at the local drafting supply store - and no one bought them. Lead Pointers Lead pointers replaced the pencil sharpener when lead holders DYING replaced pencils, and are now disappearing as new smaller leads need no sharpening. Lead pointers often had a foam "stab-me" to clean new-sharpened points. More archaic was the sandpaper pad . Manufacturers of pointers included: the heavy, metal Boston # 1401 with its sandpaper lined refill cups, and the smaller, lighter plastic models Berol Turquoise/7 and Staetdler # 502. Erasers Hand erasers remain, like the famous Pink Pearl and Staetdler's MOSTLY ALIVE white vinyl. Electric erasers existed in 1968  and are too fun to get rid of. But a few of the eraser sticks are going - types specific to ink on Mylar, like the oily yellow ones… Exotica Dietzgen "Skum-X" 140P dry cleaning pad was white dust in a DEAD bag to pat on a pencil drawing in the hope of keeping it clean. I remember eraser crumbs in a can to sprinkle in the same forlorn hope. Pounce filled pores on a drawing surface before drawing in ink. My sample is Dietzgen # 142 pounce, "for use on tracing cloth or vellum." Drawing Pins Thumbtacks (and tack lifters) were listed as an alternate to brads DEAD or Scotch tape in 1968  as "necessary equipment". But masking or drafting tape became popular, and Charrette, I believe, makes sticky drafting "dots". Why stick holes in your drawing? Linen & Mylar Linen was used for ink drawings as late as the early 1900s. In DEAD Building Facility's flat file drawers at Syracuse University were the linen drawings for Crouse College, built in the 1880s. Tracing cloth was mentioned in 1968 . Linen was superceded by 100% rag vellum, still used today; also briefly by Mylar, now obsolete; and now by bond paper for CAD plots. Diazo Printer Diazo printers are disappearing as CAD plots replace prints. ALIVE & DYING This has reduced ammonia fumes in the architect's office (offices were rarely vented) and the problem of disposing of gallons of dirty ammonia. Commercial printers continue to use Diazo. Bluelines are obsolete, replaced by blue lines. Blacklines are rarer, replaced, largely, by CAD plots. Sepia prints are being replaced by photocopies onto vellum. There were two varieties of sepia: expensive erasable sepias (ugly, but erased) and regular sepias. For those you used sepia eradicator fluid with a little brush… ugly, soggy, and smelly. Flat-Bed Printer Pinbar drafting required a flat printer since the pinned together wad EXTINCT of drawings would not feed through a Diazo printer. Drawings were aligned face down on a huge light table. Light sensitive print paper was set on top and a hinged lid (plastic with a thin foam) was closed. Then a vacuum pump sucked air out of the printer, theoretically eliminating air between the layers so that all would print clearly. In practice, seals were faulty and air bubbles persisted. The printer spent much time smoothing the lid, placing weights (books or bricks), and flattening himself there too. After the print paper was exposed, it was run through the developer a Diazo machine to raise the image. Gone now. Good. CAD Computer Aided Design is alive and well, but there were a few VERY ALIVE W/ caveman versions that are now quite dead or, at least, evolved… DEAD RELATIVES Mentioned in 1968's  were: the DAC-1 Digital Graphic Input/Output System (with display console and image processing unit), the IBM 2250 Display Unit, the Digital Drafting System by Benson-Lehner, the Gerber Plotting System, the Orthomat by Universal Drafting Machine Corp., the Coradomat, the Calcomp System by California Computer Products, and the IBM 1620 Drafting System with the 1627 Plotter. .