Wood color.

[Michael Szyper]

3 hours ago, MikeC said:

I don't think winter growth in maple is very visible in any case.   Winter grain in spruce and grain reversal can be an issue.  

It is not visible if you don’t look for it.

[Michael Richwine]

12 hours ago, Don Noon said:

Do are these fugitive when mixed with oil varnish, like many other dyes?  Are they transparent?

Yes, they are totally transparent.   Light fastness in absolute terms varies somewhat by color, since almost any color fades under UV, but these metal - based dyes are the least fugitive of all dyes known at present, far more stable than any aniline or vegetable dyes.  I used them in commercial wood finishing systems for a long time. My USP as a custom finisher is that I could do furniture factory quality finishes on architectural / residential interiors which no painting contractor could match at the time. Seems nobody else had bothered  to learn the fairly rudimentary skills at that time.

[Nick Allen]

2 hours ago, Michael Richwine said:

Yes, they are totally transparent.   Light fastness in absolute terms varies somewhat by color, since almost any color fades under UV, but these metal - based dyes are the least fugitive of all dyes known at present, far more stable than any aniline or vegetable dyes.  I used them in commercial wood finishing systems for a long time. My USP as a custom finisher is that I could do furniture factory quality finishes on architectural / residential interiors which no painting contractor could match at the time. Seems nobody else had bothered  to learn the fairly rudimentary skills at that time.

I have the full suite of Orasol dyes. Perhaps I could experiment with them to reach a satisfactory result. 

[David Burgess]

2 hours ago, Michael Richwine said:

Light fastness in absolute terms varies somewhat by color, since almost any color fades under UV,

Agreed, but l'll add that light fastness also varies by the medium into which colors are mixed.

[Melvin Goldsmith]

12 hours ago, Michael Szyper said:

Keep in mind that in the old stuff you don’t see winter growth on maple at all, just compare dons picture. IMO this detail rules out heat treatment and alkalis for color as the only color source in the wood.

Yes That is because the wood is sized ( not sealed) and a golden 'stain or layer is applied over that which sinks into the size a bit. Most likely one or two thin coats simply of what will be the colour varnish. This takes out the maple growth lines and the loss of the maple growth lines is most apparent on near mint condition examples. Where there has been considerable wear on some examples it is less apparent. Once the size has been stained this way a clear layer is applied to give visual relief to the 'ground' and several more coats of the same colour are applied to build up to an orange red type colour that we think of as the colour coat. 

[David Burgess]

4 minutes ago, Nick Allen said:

I have the full suite of Orasol dyes. Perhaps I could experiment with them to reach a satisfactory result. 

Please do, and get back to us with your results.

[charliemaine]

4 minutes ago, Melvin Goldsmith said:

Yes That is because the wood is sized ( not sealed) and a golden 'stain or layer is applied over that which sinks into the size a bit. Most likely one or two thin coats simply of what will be the colour varnish. This takes out the maple growth lines and the loss of the maple growth lines is most apparent on near mint condition examples. Where there has been considerable wear on some examples it is less apparent. Once the size has been stained this way a clear layer is applied to give visual relief to the 'ground' and several more coats of the same colour are applied to build up to an orange red type colour that we think of as the colour coat. 

What type of sizing(s) were applied?

[JacksonMaberry]

54 minutes ago, David Burgess said:

Please do, and get back to us with your results.

Yeah, thanks Nick!

[JacksonMaberry]

Mike Molnar's paper on casein norbixinate size would be worth a read, re a rich colored size. 

[Nick Allen]

1 hour ago, JacksonMaberry said:

Mike Molnar's paper on casein norbixinate size would be worth a read, re a rich colored size. 

Link?

[Melvin Goldsmith]

3 hours ago, charliemaine said:

What type of sizing(s) were applied?

Historically verifiable mediums as would been used in art use....not many options but adjusting the chosen medium for the purpose might be the key

 

[David Rosales]

1 hour ago, Nick Allen said:

Link?

Maybe this one? I don’t have a subscription to verify. 
 

https://www.thestrad.com/lutherie/optical-effects-in-lutherie-reflected-glories/13643.article

[John Harte]

9 hours ago, Don Noon said:

And, while I'm at it, some close-ups of the Titian and Willemotte, from Strad3D:

Just to add a little more to what Don has illustrated.

Lighting and light direction are critical in terms of what is or isn't seen, especially on these instruments.  Some shots (Titian) below will hopefully illustrate this.

The first two feature spruce, the first with light along the grain and the second with light across the grain.  Note what reflects light and what doesn't in each.  These were taken through an illuminated magnifier.  The third shot is obviously maple and was taken under room lighting.  The fourth and fifth shots are maple, again taken under the illuminated magnifier with the light aligned along the grain.  Unfortunately I haven't a shot of the maple with light aligned across the grain but a similar thing happens to what is seen in the spruce shots. 

[Bill Yacey]

11 hours ago, MikeC said:

I used to work at a textile factory and acquired some synthetic dyes, not sure what kind though.  It looked good on some test samples and I wouldn't rule out using it on a future build although I'm trying to go all natural. 

That company's claim to fame is that they made the fabric for the green jacket of the Masters golf tournament.   I don't have any of the green dye though, just some red that they used on billiard felt.  Yeah there are red billiard tables out there somewhere.  There was even a bright neon pink that one customer ordered.    

When I was a kid, the old pool hall / barber shop in my grandparent's town had red felt on all the snooker tables. I thought this was typical.

[MikeC]

4 minutes ago, Bill Yacey said:

When I was a kid, the old pool hall / barber shop in my grandparent's town had red felt on all the snooker tables. I thought this was typical.

I always thought pool tables were green, not sure about snooker.   The company I worked for (Forstmann) made a variety of colors.  I used to get their seconds and sell it on ebay with instructions on how to cover a table.  Had a little gold mine there for a while till they went out of business.  

[JacksonMaberry]

15 minutes ago, John Harte said:

Just to add a little more to what Don has illustrated.

Lighting and light direction are critical in terms of what is or isn't seen, especially on these instruments.  Some shots (Titian) below will hopefully illustrate this.

The first two feature spruce, the first with light along the grain and the second with light across the grain.  Note what reflects light and what doesn't in each.  These were taken through an illuminated magnifier.  The third shot is obviously maple and was taken under room lighting.  The fourth and fifth shots are maple, again taken under the illuminated magnifier with the light aligned along the grain.  Unfortunately I haven't a shot of the maple with light aligned across the grain but a similar thing happens to what is seen in the spruce shots. 

Lord have mercy, thanks John... Wow.

[Michael Szyper]

16 hours ago, Melvin Goldsmith said:

Yes That is because the wood is sized ( not sealed) and a golden 'stain or layer is applied over that which sinks into the size a bit. Most likely one or two thin coats simply of what will be the colour varnish. This takes out the maple growth lines and the loss of the maple growth lines is most apparent on near mint condition examples. Where there has been considerable wear on some examples it is less apparent. Once the size has been stained this way a clear layer is applied to give visual relief to the 'ground' and several more coats of the same colour are applied to build up to an orange red type colour that we think of as the colour coat. 

Couldn’t agree more.

[MikeC]

14 hours ago, Melvin Goldsmith said:

Historically verifiable mediums as would been used in art use....not many options but adjusting the chosen medium for the purpose might be the key

 

What do you mean by adjusting the chosen medium?  

By 'sized' do you mean just a light coating to prevent end grain blotchiness?  

[Don Noon]

For the last month, I have been running a UV test on spruce and maple, and torrefied samples.  9 days were clear enough to put out in the weak-ish January sun, otherwise it was in my wimpy 80W lightbox day and night.  Half of the wood was covered with aluminum foil to preserve the original color.  The spruce was from the same Engelmann log, and the maple was from the same European maple board.

Spruce is on the left, and the upper and lower images were taken with a different lighting direction.  Spruce is extremely reflective with the light perpendicular to the grain.  The torrefied wood is hopefully obvious.

The fresh wood does the expected thing of heading toward yellow/orange/brown with exposure to UV, and the torrefied wood starts out quite brown, and lightens to a more grayish appearance.  I may take these sample out in the Summer to see if the stronger UV and UVB makes any difference.

I also did some maple tests with ground (terpene) and clear varnish (Epifanes boat varnish) to see if that blocked any UV effect, and as best I can tell, the UV effect is about the same as bare wood.  Pigments probably matter, but I'm not about to get into that.

Another note is the darker annular rings with the torrefied wood, and the difference remains after UV.  I have a complex reasoning why all that happens, which I won't go into now.

[JacksonMaberry]

Fascinating, thanks Don!

[Davide Sora]

Thanks for sharing, Don.

 

[Davide Sora]

23 hours ago, Don Noon said:

the torrefied wood starts out quite brown, and lightens to a more grayish appearance. 

Do you have any idea why the color lightens?

[Don Noon]

5 minutes ago, Davide Sora said:

Do you have any idea why the color lightens?

Nope.

One other thing... the torrefied wood looks extremely dark when put next to fresh wood... but without the direct comparison, it's not so bad.  Also, it has been my observation that most old violins are very dark, but you don't notice it so much until compared directly to a new instrument (but various pre-darkening measures can compensate, sortof).

[David Rosales]

21 minutes ago, Davide Sora said:

Do you have any idea why the color lightens?

Maybe it’s a form of sun bleaching, the same way our hair color gets lighter in the sun?

[MikeC]

Does torrefing / torrefaction?  what's the right word,  anyway does that involve heating in the absence of oxygen?   I thought that would partially carbonize the wood as in making charcoal but would not expect carbon to lighten under UV.