Walking the Norte, we came across a wall which had lots of sculptures in it, including a corner stone with a face on it which could be viewed from two directions. The owner asked us if we would like a stamp for our credenciales, and beckoned us into his garden, which was also an entrance to his open fronted workshop. We handed him our credenciales and to my surprise he fired up a gas welding torch, as if he was going to burn them... but then produced some sealing was which he melted, dripped onto the paper and pressed a sello into it, which took the shape of a medieval cross. In the meantime I was very taken with all his sculptures so he invited us into his home to see more. This turned out to be one of the most interesting encounters of the whole camino. Inside his house was a granite pillar, with ivy leaves carved in relief bearing all his family members for three generations, it must have taken years of work. His carvings were lovely, I bought a small one for my daughter which I then humped all the way to Santiago. We were invited to lunch, classic local fare of a leg of ham and a knife which you were expected to carve lumps off, the same with the cheese and bread, and a jug of wine. Coffee followed, laced with the local fire water, I don't know what the alcohol in the coffee was but we ended up drunks as lords, and somewhere further down the line we fell asleep under a tree until we had sobered up enough to walk to the alberge. I still smile with pleasure at the memory of that afternoon when I look at the stamp, it is definitely the most eye catching on my credencial.
So to answer your question, my sello would definitely take a similar format and be one with a relief for stamping in sealing wax.
