Which pigment?


Recommended Posts

The attached picture and video shows Ha-Na Chang with her Guadagnini Cello. The color of the varnish shows a nice light amber which can varies a lot under different color of light and remember me a bid of the "Goore-Booth" Strad Cello.

This color is rarely used today by contemporary makers and shows not much for "madder-lake" fans. The right ground is important follow by....?

What an amazing performance! (Headphones and listen).

post-1262-0-22349700-1290884884_thumb.jpg

Link to post
Share on other sites

post-6284-0-00408800-1290905628_thumb.jpgpost-6284-0-70699400-1290905602_thumb.jpg

The attached picture and video shows Ha-Na Chang with her Guadagnini Cello. The color of the varnish shows a nice light amber which can varies a lot under different color of light and remember me a bid of the "Goore-Booth" Strad Cello. This color is rarely used today by contemporary makers and shows not much for "madder-lake" fans. The right ground is important follow by....? What an amazing performance! (Headphones and listen).
Michael, Here is a cello I did with this kind of color. In some lights it appears quite pale, in other a deep burnt amber color. The coloration is color from the varnish + a small amount of bone black in the top coats.

Rainer Beiharz won a Certificate of Merit for his cello at the recent VSA competition. The color on the cello was very similar to the Guad.

on we go,

Joe

Link to post
Share on other sites

Hi Michael,

Hans Pluhar, a very good contemporary instrument maker whose work I admire, quite often does a varnish that has this kind of straw or honey-colored look. He pulls if off really well. It is a challenge on an instrument that is not antiqued, but Hans' fiddles to my eye are very attractive. http://www.hanspluhar.com/instruments.html I sometimes worry that many of us are varnishing a bit too dark, too much pigment, etc...I worry that the linseed oil and wood may change over a few hundred years to push the color even darker.

Kelvin

Link to post
Share on other sites

Hi Joe! That become a nice cello. I like the run of the flames change from upper to lower bout.

Hi Michael,

Hans Pluhar, a very good contemporary instrument maker whose work I admire, quite often does a varnish that has this kind of straw or honey-colored look. He pulls if off really well. It is a challenge on an instrument that is not antiqued, but Hans' fiddles to my eye are very attractive. http://www.hanspluha...nstruments.html I sometimes worry that many of us are varnishing a bit too dark, too much pigment, etc...I worry that the linseed oil and wood may change over a few hundred years to push the color even darker.

Kelvin

Hi Kelvin,

you are absolute right. It is really a challenge if a Instrument is not antiqued. The visual effect of this can change a lot. I think it is not only a question of color or pigment. More of how is/was it applied, in one or more layers. The top of the Guadagnini on the photo in this light looks for me just shellac rubino over a perfect closed white wood plus 250 years.

Here is a close-up photo from the Ole-Bull del Gesu rib and one of my scrolls. (Both taken with a dream of Hasselblad cameras) You see the yellow layer on the del Gesu is thinner and closer to the wood wich gives a better dichroism effect too.

post-1262-0-04255900-1290940528_thumb.jpg

post-1262-0-74712000-1290940543_thumb.jpg

Link to post
Share on other sites

The color of the varnish shows a nice light amber which can varies a lot under different color of light and remember me a bid of the "Goore-Booth" Strad Cello.

This color is rarely used today by contemporary makers and shows not much for "madder-lake" fans. The right ground is important follow by....?

Hi Michael,

Here are three shots of the same spot on the back of the 'Gore-Booth' only the lighting angle changes. If you flip through them quickly it's like turning the wood under a light. Mostly it is for those who haven't seen this cello in real life.

Edit: I attached the same photo twice! It is now correct.

Bruce

post-29446-0-65351400-1290978391_thumb.jpg post-29446-0-79064900-1290977993_thumb.jpg post-29446-0-77342500-1290978004_thumb.jpg

Link to post
Share on other sites

Hello Bruce,

thank you for the pictures, very nice! Come this color very close? It looks a bid different compare to the book of the 1987 exhibition and the full-size posters I have it from "Cremonabooks".

Michael,

The problem is always the lighting and the printing. It's never the same. Sometimes when I look at this cello it is decidedly yellow-gold. In a different light it is closer to orange. The 1987 catalogue they are photographed and printed as if they were under bright lights.

EDIT: Here is another shot under brighter light; perhaps slightly over-exposed.

Bruce

post-29446-0-45563300-1290980640_thumb.jpg

Link to post
Share on other sites

Oded,

I want to try your madder/alcohol tincture, but I don't really like using shellac as my ground (because it is so darned hard to strip off if I don't like it.) Could it be mixed with oil varnish, perhaps in an intermediary solvent like xylene? Or perhaps spirit varnish could be used as rgound?

Thanks.

Doug

p.s. Bruce, I always enjoy seeing your photographs. I have learned a lot from them.

Link to post
Share on other sites

Doug Rice wrote:

I want to try your madder/alcohol tincture, but I don't really like using shellac as my ground (because it is so darned hard to strip off if I don't like it.) Could it be mixed with oil varnish, perhaps in an intermediary solvent like xylene? Or perhaps spirit varnish could be used as ground?

You can use any alcohol soluble resin such as mastic, sandarac, lightly cooked Venice turpentine, rosin (if you don't build it up too much),various shellacs,and any number of synthetic art restoration resins that are alcohol soluble.

I don't use this method for coloring an oil varnish.

Oded

Link to post
Share on other sites

There are a couple of different ways to do this. Mix the madder (I often also add pernambuco sawdust) with alcohol and keep warmed for a day or two, filter out the tincture. Then concentrate the color by evaporating some of the alcohol, add dissolved resin to the tincture, or dissolve the resin directly in the tincture. Madder is very pH sensitive, any contact with a base will turn it red to purple. Adding a little tannin helps to stabilize the color. Too much tannin will react with any iron and turn it black. Oxalic acid will prevent tannin from turning iron black. Tea contains both tannin and oxalic acid.

Oded

Link to post
Share on other sites
  • 4 weeks later...

Thanks Melvin.

The color was the customers wish. The wood is very nice and hard to find this days for Cellos.

I will take some photos after the set-up is done wich is in the middle of January and post it. First I was thinking to send it to Jan Röhrmann, but I decided to take it here with some help in a studio, because my own daylight bulbs are not strong enough for a cello. I tell later about the color and varnish.

Link to post
Share on other sites
  • 4 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    No registered users viewing this page.