Nearly all of the artefacts recovered from the Invincible had an arrow marked on them in some way. In antiquity, various means were used to mark the object with the arrow as follows: -

Stamped:- known as being impressed, this method was certainly used in 'harder' materials such as copper. A metal stamp was used in the normal way.
Incised:- Meaning to scribe. Quite simply the manufacturer of the original object took a knife or scribe and scratched the arrow into the surface. Most of the leatehr buckets were marked using this method. Also on the ends of the sand glasses (see image below) were scribed broad arrows. Interestingly, some of the very hard lignum vitae (also know as 'Iron Wood') sheaves were crudley marked in this manner. See link to 'Sheaves' page.
Even in modern times, broad arrows, sometimes known as 'crows feet', are used to identify property belonging to her majesty's government. In the early days of the project, during lectures and talks given to various societies etc., much debate often took place as to the origin of the 'broad arrow'! Arthur felt therefore, that in order to complete the story of these artefacts accurately, research should be conducted in this area. Together with friend and colleague Les Dury, Arthur came across a very interesting document in the public records office in London U/K.
The 'Broad Arrow', the Government property mark, originates from 1330, viz:
An illustration of a document dated 1330 issued by Richard de la Pole, the Kings Butler, for the purpose of wine and bearing his seal. This shows that in order to make sure that ownership could be readily established as Kings property, he marked each item with an arrow from his own coat of Arms. The date on this document was 1330! This pre-dated all of the speculative advice given by many historians.
Here we see an example of a "Incised" broad arrow on a leather bucket. This image taken with bucket in "seabed" condition before conservation work.
Above - As you can see from these three spare ends of sand glasses, the 'Broad Arrow' has been very roughly "Incised" into the soft pine wood.

This copper staple was "Stamped" with the broad arrow. After more than 200 years on the sea bed being eroded by tidal action, it is amazing to see the stamped broad arrow has eroded at the same rate as the surrounding copper, thus leaving the mark clearly distinguishable.