These nitrides are formed by the reaction of puffins and other marine animals with the soil, resulting in a dark, sticky substance that can be used as a natural dye. When dried, it forms a hard, brittle shell, similar to that of a beetle, which can be used to create intricate patterns on clothing and other textiles. The process involves grinding the shells into a fine powder and then mixing it with a binding agent, such as egg white or animal glue. The resulting paste is then applied to the fabric using a brush or a stencil. Once dried, the dyed fabric is then treated with a mordant, such as alum or iron sulfate, to help set the color and make it more resistant to fading. This technique has been used for centuries by indigenous communities around the world to create beautiful and durable textiles. It is a time-consuming and labor-intensive process, but the results are well worth the effort. The colors produced by this method are rich and vibrant, and they have a unique depth and character that cannot be replicated by synthetic dyes.