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Corduroy makes the top less boring to look at.

It can be achieved by scraping, wetting the top with water and applying varnish carefully, following some smart plan.

I know from drying instruments in a rather hot uv-box, that corduroy can also occur as a result of the spruce drying out (important for this case, in the trunks tangential direction): the late wood shrinks more than the early wood because the late wood is more compact. So there will be a valley at the late wood lines, with a ridge of early wood in between.

I believe drying when aging must have that same effect.

Old instruments with soft varnish often have a curdoroy-ed surface, like the Messiah.

Did Stradivari &Co intentionally give the tops a corduroy surface?

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Did Stradivari &Co intentionally give the tops a corduroy surface?

Hi Salve,

You ask a really good question. I look forward to some interesting contributions on this. Thanks.

Right now my feeling is that the old Cremonese did not do a corduroy effect intentionally ( I think we see it with ingrained patina in grain lines more in celli than violins perhaps indicating that their smoothing process was quite laborious)and I feel that what we see on the Messiah is as you suggest the result of drying and shrinkage with aging...Just like they did not ripple the surface of their backs with the flame intentionally.... :)

In my own making as you describe with yours I find a corduroy effect can develop in the light box or over several years. Certain types of varnish might allow this more than others. Certainly on the other hand with a lot of old 'trade' instruments with very unforgiving varnish we do not see this much.

Looking at the old Cremonese wood finish I am mainly amazed at how smooth it is given the tools available and this makes me think that 'smoothness' judged by the criteria of the day was important to these makers....With a Venetian instrument I am copying right now there are very obvious but smoothed tool marks on the wood possibly from a glass scraper...In this case I think a clear coat of varnish was manipulated to smooth the surface.

Some old Cremonese instruments have the opposite of the corduroy effect....which we might expect from burnishing but is probably from wear and tear and being pressed into casts

.

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Salve, your comment that the denser winter grains of spruce would shrink more than summer wood upon drying make no sense to me the larger cells of the summer wood have thinner walls and more space inside which would be filled with liquids and would collapse as the liquids exited the cell giving the opposite effect from what you describe. As stated in several posts yesterday the corduroy effect on violin tops is caused by scraping to smooth the wood rather than sanding if you want to get some other surface you must do some further step such as sizing the top with glue and rescraping after it drys. The comment by Melvin that we don't see the corduroy on trade violins is that those violins were sanded either after or instead of scraping.

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Old guitars, I'm using them as an example here because their tops are often sanded smooth and highly polished, tend to show shrunken soft grain lines. This gives an opposite kind of corduroy effect than is seen on the Andrea Guarneri tenor viola.

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Raised summer growth is quite prominent on all well-preserved examples I have seen. I agree with William and Nathan that shrinkage over time tends to go in the other direction, at least on all my samples which started out smooth.

Was it intentional? I don't have any way of knowing, but I suspect that it's just an artifact of the tools and methods they used. Why bother to get rid of it?

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Here's a detail of the Messiah lifted from Darnton's website:

post-25192-0-33248800-1337906278_thumb.jpg

I'm with Melvin. It looks to me like the majority of the corduroy happened after the varnish was put on; otherwise, I would have expected to see much more varnish and color in the valleys.

I don't think there is any way to argue which grain (summer or winter) shrinks more, just by thinking about it, as it seems to me that it's the chemical composition that controls the shrinkage, rather than how much space there is or how thin the walls are. I took a look at some of the wood in my stockpile, and all of it shows the lower density wood puffed out above the grain lines... with one exception: a couple of grain lines on a very low density piece have collapsed in, likely due to surface tension of wet wood during drying. In any case, it's impossible to tell if the usual condition is due to rebound of compression during cutting/planing, or actual shrinkage.

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It looks to me like the majority of the corduroy happened after the varnish was put on; otherwise, I would have expected to see much more varnish and color in the valleys.

It depends on how "self-leveling" the varnish is. I've had varnishes turn out much like that, but in my case, it wasn't intentional. I prefer the look of varnish which levels a little more.

To me, it also looks much like what you get when you put 1704 over scraped, unsanded wood. Maybe that has something to do with claims that 1704 was Strads varnish.

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Here's a detail of the Messiah lifted from Darnton's website:

post-25192-0-33248800-1337906278_thumb.jpg

I took a look at some of the wood in my stockpile, and all of it shows the lower density wood puffed out above the grain lines...

Do you know if this wood was flat when the surface was freshly milled? Sometimes the powertool used to process the wood can give it that look.

Seriously, guitars are made with tops that are sanded flat and the laquer is polished to a high shine. They are an ideal place to see which way the grain shrinks with age. They don't end up with a Cremona style of txture with age. In addition you don't get the texture along the grain lines seen in the photo above, or on the A. Guarneri tenor, through age. That would be require some really funny shrinkage to happen. However, with a dullish scraper you automatically get that texture and the soft grain lines standing above hard lines.

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FWIW

I sanded the spruce on this violin to a very smooth surface before varnishing, and then sanded afterwards to produce a shiny surface (corduroy had not been invented then).

Fast forward, and the wood and varnish have done some interesting things.

post-24474-0-41333800-1337912859_thumb.jpg

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I'm with Melvin. It looks to me like the majority of the corduroy happened after the varnish was put on; otherwise, I would have expected to see much more varnish and color in the valleys.

Hi Don;

This is just my opinion.

I wasn't there, so I can only observe what I have a chance to see. Based on that, my impression is that on many of the classic fiddles with prominent texture, a good portion of that texture was present at the time of varnishing... but I also believe a portion of it may have "developed" as the varnish cured and the instrument cycled (as long as it wasn't messed with). I've seen this occur to a limited degree on instruments I've worked on (when they return to me later on).

As far as the more varnish/color in the valleys, I believe this may be do in great part to the application as well as (as David mentioned) the ability of the coating to self-level.

How "close" the color is to the wood, or the effective use (or not) of an isolation layer, has a rather significant effect as well. The color is actually "pushed" into the upper layer of the spruce by some makers. You can observe soak-in on some tops, making the summer grain appear as dark or darker than the winter grain while still retaining texture in the spruce (a later, but extreme case of this would be Pressendas made in the 1830s).

Best to all,

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Hi Don,

In that image of the Messiah I think Michael said that the contrast is enhanced, to illustrate a point pertaining to varnish and wood texture. It's not a model image in my opinion.

I have never seen the violin in person, would anyone care to comment, that has seen it?

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FWIW

I sanded the spruce on this violin to a very smooth surface before varnishing, and then sanded afterwards to produce a shiny surface (corduroy had not been invented then).

Fast forward, and the wood and varnish have done some interesting things.

That's "reversed grain" in your photo, like the kind of shrinkage Johnston has noticed on guitars.

On whether raised summer growth can become more prominent with time:

It can, if the compressed summer wood (from tooling) was never released by moistening. In that case, time and some humidity cycling will let the summer growth expand in the direction of its natural, uncompressed state, if the filler/varnish allows.

When I've prepared wood with a plane sharp enough not to compress the wood (a fresh razor edge), it doesn't happen, although I can sometimes swell the soft grain a tiny bit with hot water.

In that image of the Messiah I think Michael said that the contrast is enhanced, to illustrate a point pertaining to varnish and wood texture. It's not a model image in my opinion.

I have never seen the violin in person, would anyone care to comment, that has seen it?

The raised summer grain is clearly visible in person. One problem with general acceptance of this feature is that it doesn't show on standard, straight-on fiddle photos, where reflections are minimized. It's most easily seen when the lighting angle is such that there are strong reflections.

And, of course, it's easily messed up by wear, polishing, pressing the top into molds, etc. I think it's fair to say that it's mostly gone on the majority of Strads. Would you agree, Jeffrey, Roger or Bruce?

In person, the Messiah doesn't appear to have much puddling in the low spots, like the winter grain. The varnish texture on the rest of the instrument also suggests that this varnish didn't self-level much.

With wear, the varnish in the low areas would tend to remain, accentuating the dark grains more.

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...

Fast forward, and the wood and varnish have done some interesting things.

Perhaps you sandend the varnish smooth while the spruce was in a dried out state. Like coming from the sun or an uv-box?

If you did, the explanantion for its current texture follows nicely from my post #1:

The latewood has now swelled back out (more than the earlywood), so the latewood makes a ridge.

I predict that after many more years, the latewood will have shrinked again, from age, and those "reversed grain" ridges will dissapear!

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A question:

On corduroy violins, is the same effect seen on the inside?

For those that have seen inside the big boys, is there any indication of this?

I've always assumed that the inside is finished differently the the out. I tend to sand the inside after scrapping to get a nice, smooth, rounded look towards the gluing platform.

If the corduroy effect is from shrinkage after the instrument is finished, wouldn't one expect to see much more inside, where the wood is more exposed/unvarished?

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So, if we want to make a fiddle that is properly antiqued... we need to get rid of the corduroy. :rolleyes:

Heh heh. :)

What I encourage is taking antiquing inspiration from some of the better preserved instruments, or cheating a little bit in the direction of more original condition. If that's done judiciously, people who want an intiqued instrument don't seem to mind.

And what's the alternative? Keeping pace with the more worn and still-used instruments as they become ever more hammered and featureless?

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On corduroy violins, is the same effect seen on the inside?

For those that have seen inside the big boys, is there any indication of this?

I would expand the question to other (cheap) old fiddles:

For those fiddles with the interiors left in the as-gouged condition, is there any corduroy? They would not be subject to scraper compression or uncertain sanding effects... if they are cleanly cut, I would expect this to be the best test of natural shrinkage.

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The raised summer grain is clearly visible in person. One problem with general acceptance of this feature is that it doesn't show on standard, straight-on fiddle photos, where reflections are minimized. It's most easily seen when the lighting angle is such that there are strong reflections.

And, of course, it's easily messed up by wear, polishing, pressing the top into molds, etc. I think it's fair to say that it's mostly gone on the majority of Strads. Would you agree, Jeffrey, Roger or Bruce?

I'd say that's fair. I think it's also fair to say that even dealing with relatively untouched instruments, the amount of texture varies a bit (from maker to maker as well as dealing with the same maker).

I would expand the question to other old fiddles:

For those fiddles with the interiors left in the as-gouged condition, is there any corduroy? They would not be jubject to scraper compression or uncertain sanding effects... if they are cleanly cut, I would expect this to be the best test of natural shrinkage.

Well... I can say that a number of instruments (with texture on the outside) that I've had open exposing interiors that haven't been messed with too much do show some texture on the inside... though not as pronounced as the exterior... but your question has a modifier... "as gouged condition". Not sure I have an answer that one. I think there is a bit, but I have to admit my attention is drawn to other things when it comes to the rougher interiors. Maybe Bruce or Roger will comment.

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Heh heh. :)

What I encourage is taking antiquing inspiration from some of the better preserved instruments, or cheating a little bit in the direction of more original condition. If that's done judiciously, people who want an intiqued instrument don't seem to mind.

And what's the alternative? Keeping pace with the more worn and still-used instruments as they become ever more hammered and featureless?

Hi David,

Here's a shot of the surface of a late Stradivari cello where you can see the effect you described. It is an instrument that clearly has a scraper finish and has some of the corduroy appearance. On the right side the varnish is unworn and the color is uniform and does not show any buildup over the late summer / autumn growth. In other areas where the varnish has been worn away the visual contrast increases making the rings jump out. The varnish appears to have some ingredient causing a veiled opacity; likely a pigment or mineral color.

Unfortunately I don't have a shot of this same area in reflected light which would show the strong corduroy ribbed effect. Pretty heavy scraper work.

On the left of the photograph is under the fingerboard which is not bare wood but "less varnished" and mingled with dirt.

Bruce

post-29446-0-02961100-1337974450_thumb.jpg

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The question about whether the insides of violins have the corduroy effect is an interesting one. My own recollection of the inside of classical instruments is that I've never seen the kind of strong uniform corrugation on the inside that I've seen on the outside. In my own making I know that while some corduroy is inevitable with scraping the really strong effect requires a deliberate effort. There are several mint condition instruments that I have seen that I am sure were made to deliberately maximize the corrugated effect. The nicest example I can think of is a Venetian violin at the shrine to music museum I beleive a Linarol. I have also seen many fine instruments where there was a deliberate use of texture to acheive certain effects for instance a great F. Ruggieri that had the most plastic and fluidly carved scroll where the fluting was not scraped at all but finished with a gouge alone leaving a random pattern of 1 to 2 millimeter gouge marks all over. Since there is no question that these guys had the technical ability to make things as smooths as they wanted to the only conclusion I can beleive is that the surface we see is the one they intended.

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Since there is no question that these guys had the technical ability to make things as smooths as they wanted to the only conclusion I can beleive is that the surface we see is the one they intended.

Or maybe a higher priority than smoothness and cleanliness was putting spaghetti on the table. With the passage of time, we came to appreciate that as art. It's not like the early Hills weren't a little less than ecstatic about Del Gesu's workmanship.

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That's "reversed grain" in your photo, like the kind of shrinkage Johnston has noticed on guitars.

The reason I commented on interesting behaviour of the varnish/wood is that the violin shown (spirit varnish) has developed the reversed corduroy effect, while the top surfaces of ones varnished with Fulton's (Northern Renaissance version) remain as sleek as glass.

Similar wood preparation involved.

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Nobody has mentioned one downside to corduroy: either you need to carve rippled bridge feet (does anybody actually do that?), or the feet will sit on the puffy low-density wood, and quickly dent it. Maybe that's OK... it'll just squish down until everything's level.

Personally, I'd prefer the bridge area to be a little smoother than the rest of the top, just to get a better surface for the bridge. And I also personally prefer minimal corduroy... just enough to be apparent. Subtile, not like a log cabin wall. I figure it will get more testure as the wood ages and the varnish shrinks down.

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I've been experimenting with burnishing the wood with a smooth polished stone, followed by a final scraping. The burnishing tends to compress the softer, low density wood. After it's scraped, if you wipe the wood down with a damp cloth, the soft wood expands and you have instant corduroy.

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