resawing issue

[Rusty Elam]

I am building a walnut blanket chest and have run into a interesting issue maybe someone can explain to me. I am making it frame and panel out of solid walnut, when I resawed some 3/4 walnut to make bookmatched panels approx. 11/32nds thick I noticed after they came out of the planer and were glued up that the panels that had figure in them looked different on the two sides. The bookmatch looked right but when you look at them (especially from the side) one side of the panel looks very dark and the other side looks light. The panels that had more or less straight grain look identical on the left and right, but the figured ones are dramatically different l to r, and when I sealed them with shellac before before assembly it shows even worse?

Any explaination of something I should of done differently?

[David DeCristoforo]

This is the nature of bookmatches. What is happening is that the light is being reflected differently by the two halves. The grain lines match but if you look at the ends of the bookmatched boards, you will see that the "slope" or angle of the grain is running in opposite directions.

[Rusty Elam]

Thanks David,

I kind of figured it was a light issue because you can look at it from the opposite direction and it reverses, the light side looks dark..dark side looks light.

I am kind of new to resawing and it made me think I might of screwed up.

[Peter Quinn]

I've seen this used to very interesting effect. Simple pieces of maple, nothing particularly figured, arranged in squares like a checker board, each square oriented at 90 degrees to the one next to it. Looks great once finished. Looks like they were dyed different colors depending on where you stand. Saw something similar done with figured walnut wall tiles, those I actually made unfortunately,, very boring making 2000 5X5 squares of figured walnut!

I like the effect personally.

[Steve Jenkins]

for those who might be interested it's called chatoyance.

[Glenn Howard]

As others have said, this is fairly common with bookmatching. You can see this quite often with electric guitars. Take a look at some Gibson Les Pauls. They are made of mahogany, with an arched top (or cap) made up of bookmatched maple. Gibson typically does a great job with ensuring a quality bookmatched job (as they should for a $2000-$5000 instrument). But what you will see with a lot of the knockoff brands are bookmatched caps with issues just as you've described.

[Brad Shipton]

I did my first test with book matched/end matched panels for a door and am experiencing the same. I would be interested to hear if there is anything one can do to improve upon this. To me it seems purely a function of the piece of wood.

Brad

[David DeCristoforo]

"I would be interested to hear if there is anything one can do to improve upon this."

No because...

"To me it seems purely a function of the piece of wood."

...it is. You can try coloring the wood, staining the wood, whatever. But the difference will still be there and all you will accomplish in the end is to do a lot of extra work and risk "killing" the character of the wood. For what it's worth, there are many woods that exhibit this phenomenon to a much lesser degree. The more figure the wood has, the more likely you are to see this. Woods with any degree of "curl" or "flake" in the figure will be more prone to variations. Also, the density of the wood will affect the degree of "chatoyance" (thanx Steve). Woods with a more open grain will appear much more uniform since the pores tend to "fracture" the light that reflect off the surface. Try book matching a piece of plain sawn red oak and you will see very little difference between the faces.

[Brad Shipton]

Thanks for explaining David and kudos to Steve for adding the tech name. I was book matching Crotch Makore veneer. I thought I was nuts. I flipped pieces and still looked exactly as described. Now it makes sense.

Brad

[Eric Larsen]

Sell the piece for two-hundred-and-fifty-thousand dollars.

Tell prospective customers: "I bookmatched the panels to beef up the chatoyance."

[Rob Luter]

This is the nature of bookmatches. What is happening is that the light is being reflected differently by the two halves. The grain lines match but if you look at the ends of the bookmatched boards, you will see that the "slope" or angle of the grain is running in opposite directions.


A decent example of what David describes is shown below:

http://www.sawmillcreek.org/attachment.php?attachmentid=96040&