Green's Blackwall line (R. & H. Green & Co Ltd). The flag is made of wool bunting, machine and hand sewn with a linen hoist. A rope and metal clip is attached. A rectangular white flag with a blue square in the centre. A broad red cross is superimposed overall.

The house flag of Green's Blackwall Line, used by R. & H. Green after the dissolution of the Green-Money Wigram partnership. The original Blackwall Line flag was a St George's Cross on a white background. According to legend, an irate admiral objected to the flag - identical to an admiral's ensign - and a ship's officer hastily fixed a blue patch to the centre of the cross. After the original Blackwall Line was dissolved, Money Wigram retained this design, while Green used an adapted design with the red cross over the blue square.