1. here was a law made by the Ultonian knights that they should have Silver Shields made for them, and that the carved device of each should be different from those of all the others.
2. Cuchulainn was at this time pursuing his military education at the school of Buanann and Scathach; and on his return home he found the shields in process of being made. Cuchulainn repaired to the manufacturer, whose name was Mac Enge. "Make a shield for me", said he, "and let me not find upon any other shield of the shields of the Ultonians the same carved devices that shall be on it". "I cannot undertake that", said Mac Enge, "because I have exhausted my art on the shields of the Ultonians".
3. "I swear by my arms (of valour)", said Cuchulainn, "that I shall kill you if you do not make my shield according to my order." "I am under (king) Concobar's protection before you", said Mac Enge. "I shall violate Concobar's protection, then", said he, "and shall kill you besides" ; and Cuchulainn then repaired to his home.
4. Mac Enge was greatly distressed at what happened; and as he was musing over it he saw a man advancing towards him. "You are distressed", said he to Mac Enge. "I have cause to be so", said the shieldmaker ; "namely, that I am to be killed unless I make Cuchulainn's shield".
5. The man said to him : "Clear out the floor of your workshop, and spread ashes upon its floor, until the ashes are a man's foot in depth". It was done according to his directions.
6. As Mac Enge was standing, after this, he saw the same man coming over the outer wall to him, with a fork in his hand, and two prongs projecting from it ; and he planted one of the prongs in the ashes, and with the other described the devices that were to be engraven on Cuchulainn's shield. Luaithrindi, [or ' ashes-engraver',] was the name of this prong; as Dubditha said: "Were I Mac Enge, it is so I would engrave". And Dubhan [the Black] was the name of the Shield".
Sources : O'Curry, On the Manneks and Customs of the Ancient Irish 2