This Horse & Raven illustration began life as a design for bracer armor and developed into a colored mandala. The main motif is fairly modernized in comparison to authentically 'period' celtic art, but the three smaller swirls and other spiral parts of the pattern are a close representation of known stonework. 

While I did scribe the line art onto the leather (see both photos below), another person did the actual carving while I advised. The leather-working was done with a set of small chisels, with the background 'basketweave' pattern added to create depth and adhere to an early period Pre-Roman Celtic type of ornamentation.

The natural untanned color of the leather is shown.

After the leather carving was finished, the bracers were dyed a dark brown color.

The above photo shows the smaller spiral motifs worked into a larger design, which was carved into leather elbow coverings and part of this matching leather armor set. Note that, even without the larger central more 'realistic' design of the bracer, it is still easy to tell which is the horse and which is the raven.