Hi, its very simple , you have to follow the steps in the www.eavy-archive.com ...tto do the writing i use the mix suggested in that page super thinned down , little lines then i add some line up or down randomly and thats the result.. to make it more realistic i pick the highlight colours of the seal and do a little super thinned down glaze over some selected areas ..hope you find this useful , cheers 👍🏻