The three main devices (symbols) in the Able blazon are the bars, plate and arm in armour. The two main tinctures (colors) are sable and argent.
Sable, the deep black so often found in Heraldry is believed to named from an animal of the marten family know in the middle ages as a Sabellinœ and noted for its very black fur 1A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Sable. In engravings, when colors cannot be shown it is represented as closely spaced horizontal and vertical lines, and appropriately is thus the darkest form of hatching, as this method is known 2Boutell’s Heraldry, J.P. Brooke-Little, Warne, (revised Edition) London 1970, P 26. Although it may seem a sombre tone, and does indeed sometimes denote grief, it is more commonly said to represent Constancy 3The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P35.
Argent is the heraldic metal Silver and is usually shown as very pure white. It is also known more poetically as pearl, moon (or luna) 4Understanding Signs & Symbols – Heraldry, S. Oliver & G. Croton, Quantum, London, 2013, P53. In a sketch or drawing it is represented by plain, unmarked paper 5A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1847, P11.
The bar is a thin, horizontal stripe across the centre of the shield 6A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Bar, usually in groups of two or three (any more and there would be confusion with barry, a treatment of horizontal lines of alternating colours). Bars can be a distinctive and easily recognised device, early examples include those awarded by Henry III of England to the family MAUDYT Argent, two bars gules.
For easy recognition of the items on a coat of arms, and hence the quick identification of the owner, bold simple shapes are best. Hence, simple geometric shapes are often used for this purpose 7A Complete Guide to Heraldry, A.C. Fox-Davies, Bonanza (re-print of 1909 Edition), New York, 1978, P146 One of the simplest such shapes is the plain circle, known to heralds as the roundle. 8A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Roundle So popular is this charge that a shorthand has arisen for roundles of a particular colour and plate is a roundle argent, or white. Most authorities agree that the English usage signifies the “Manchet cake” or communion wafer and thus is a symbol of religious allegiance.
The Arm appears frequently in the crest of a coat of arms, often armoured and described in some detail as to its appearance and attitude. 9A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:arm It can also appear on the shield itself as a charge. The arm itself is said to signify a “laboorious and industrious person” 10The Symbolisms of Heraldry, W. Cecil Wade, George Redway, London, 1898 P92, whilst the arm in armour may denote “one fitted for performance of high enterprise” 11A Display of Heraldry, J. Guillim, Blome, London, 1679, P184