A friend wanted his personal symbol (3 wolves) painted onto his medieval shield. I created a drawing of one in a modernish Celtic style to make sure he liked it, then used Photoshop to composite 3 together onto a scaled oval (see photo below). Some parts of each wolf had to be stretched or distorted to look 'even' as they appear to be running in a circle even though the shield is an oval.

After lining them all up, I used a grid to transfer the pattern by hand onto the curved shield surface, by hand-drawing each grid square one at a time. He then was able to paint the shield.