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.
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