Thanks for the comments folks. I hope you will give this craft a whirl, especially if you are more graphically gifted than myself.
Yes, it is exactly like scrimshaw work. Originally ashes from the fire were used in the cuts and then rubbed with some animal fat. A historic variation on the ashes was the use of bark scrapings to get more color and now just about any ready ground powder with color.

I sure wish I could take credit for those beautiful spoons, but that is not my work. I just used them in another blog I did several years ago about kolrosing. I haven’t actually been practising it myself. This is my first half serious attempt at it. The craft is not nearly as easy as it appears at that level. Many of the same rules apply to kolrosing as for woodcarving, like cutting with the grain, sharp knife, nicely prepared surface, etc. However, as you can see it needn’t be intimidating for a beginner either.

Mike, an American living in Norway