Reference charts
A reference sheet promises completeness within its subject. Every letter, every status code, every prefix, every phase — not a selection of the handy ones. That promise is what makes it worth wall space: you can stop wondering whether the answer is on there.
It is the largest kind in the catalogue and it runs across most of the subjects — alphabets and codes, the geography of instruments, the tea and coffee sheets, units and paper formats, the planets and the Moon.
Because they are dense, they reward the larger print. A3 is usually the right call for anything read from more than a metre away.
DROP D
one string down · everything else unchanged
HALF STEP DOWN
every string down a semitone · same shapes
OPEN C
the deepest of the open tunings
OPEN D
the open strings are already D major
OPEN G
the open strings are already G major
THE EIGHT BLOOD TYPES
three antigens, eight types — and the one rule the whole table of compatibility follows from
THE TEN CLOUD GENERA
three levels of the troposphere to one scale, and the ten genera that live in them
THE COMPASS ROSE
the sixteen compass points with exact bearings: four cardinal, four intercardinal, eight in between
TN, VA, IPS AND OLED
what differs inside the cell · and a paper describing each mode
MAMMALS IN TIME
from the first synapsid to us · 320 million years on one axis
VERTEBRATES IN TIME
when each group appeared · five hundred million years on one axis
GREEK LETTERS IN SCIENCE
10 capitals with a shape of their own, 14 twins of Latin letters, and what each one stands for
USDA HARDINESS ZONES
the 13 zones by average annual extreme minimum — each range in °F and °C, with the a and b half-zones
THE MOHS HARDNESS SCALE
ten reference minerals and five household probes: who scratches whom
THE PERIODIC TABLE
all 118 elements: symbol, atomic number and IUPAC atomic weight in every cell — blocks in colour, lanthanoids and actinoids offset below
BASIC PHYSICS FORMULAS
fifteen formulas · every letter explained beneath it
PLASTIC RESIN CODES
the seven codes on the bottom of an article per ASTM D7611: which resin each number names and what it means for sorting
RESISTOR COLOUR CODE
the bands, the tolerances and the preferred series of two standards
ROCK CLASSIFICATION
the three classes, 24 named rocks and the cycle that links them — after USGS and NPS
THE SAFFIR-SIMPSON SCALE
five categories of hurricane wind — and how much more damage each next one does
SPEED THRESHOLDS
six thresholds where a different physics begins · every figure computed, not typed
ANIMALS
the main branches — from comb jellies to chordates · who is actually related to whom
THE TREE OF LIFE
who sits inside whom · where animals, fungi and plants actually are
VERTEBRATES
from lamprey to bird · and why "fish" and "reptiles" are not groups