Previously we added made the body of the coif and attached it to the cap. The final part left is the mantle piece. For this I've selected a simple round bishop mantle. Here it is still piecemeal, as I'm about to join the bits together. The mantle is made of 3 rows of 4in1 strips, each strip is 3 links wide.
After that though the diameter grows since the mantle is now falling on my shoulders, not just going down my neck. Therefore we need to expand it. This is done by adding extra rings. Again I'm using differently coloured links for example. Expansion of chainmaille sheets is done by adding extra links to a connecting line. Here I've added 1 extra copper link, per 3 normal ones. Thus the next row will be roughly 1/3 bigger, which will cover the increase in diameter. The same way you can contract the maille sheet and the ratio is by no means set in stone. It can be different.
Mind you you don't have to make a round bishop mantle like this, or any mantle at all. A coif can be integrated in a hauberk, or have a square mantle or one with triangles.Like this example which I found on the net. The mantle can also be worn separately from a coif and this will be my next armour project -a mantle piece.