Elm Back Ring Grain different from Belly Grain

[bubbles]

This is a question about various woods with interlocking grains.  I've noticed on the last bow I made that the surface grain seems to squiggle around quite a bit but when I look at the wood on the belly it is relatively straight.   
There will be overlapping swirls of surface grain, one curving out and the other curving the other way and they seem to flow over top of one another.  Basically, the grain to the left of the crown of the back could be doing something different than the grain on the right of the crown. The belly wood reflects a much straighter stave. 

Would you lay out the profile of the bow using the back grain or reduce the belly until the grain of the belly becomes evident and lay out the bow following the belly's grain?

[Pat B]

Bubbles, are you sure you don't have cambium on the back still. Once you get below the cambium the wood grain should be the same.

[PatM]

If the stave itself is straight then just make your layout straight. Each layer of elm can be going in a different direction every year. You'll never be able to guess which is the greater number of layers going in the same direction.

  It almost seems like Elm lays down new wood according to how the sap first flowed up the trunk in spring. As the bark loosens it seems like the sap comes up on the path of least resistance and the wood starts growing reflecting that trend.
  I have an elm stave that had arrow straight bark lines and it split out straight but the outer growth ring looks like somebody did diagonal brush strokes across it randomly.

[Peacebow_Coos]

Never worked Elm, but I'd say if it split straight then lay it out straight.

[bubbles]

Yeah, all the cambium is off.   PatM what you're describing seems to be what I'm seeing. The top layer just doesn't seem to go with what the belly is telling me. As well as the split, which is dead straight.  This is on one of your elm billets you hooked me up with a while ago. And I know you like straight wood.

[JonW]

Pat is right on. Elm can have some crazy looking grain under the bark.

[bowandarrow473]

Don't think twice about it, when I first cut an elm I almost threw is away due to all the squiggly lines. It scared the crap out of me to tiller that bow, but it turned out well.