an online portal for guitarmakers, guitar enthusiasts, and students
following Natelson & Cumpiano's treatise, GUITARMAKING: Tradition & Technology
Chapter 6 - The Rosette
Authors' commentary and additional suggestions
Referred from MATERIALS FOR SELF-ASSEMBLED ROSETTES
Referred from PROCEDURE: Excavating the rosette channels
What you should know about sea shells
If you’re interested in processing dimensioned strips of Mother of Pearl (MOP) and abalone from the raw shell material for inlaying guitar edges and rosette rings, you can still purchase the shells commercially. However, the market is highly regulated, and availability depends on the specific species, harvesting methods, and international trade laws. This is because the industry has adapted significantly to conservation efforts and wild population declines, shifting heavily toward sustainable aquaculture and specialized composite materials.
1. Mother of Pearl (MOP)
Mother of pearl is widely available and faces fewer legal restrictions than certain abalone species because the vast majority of commercial MOP comes from the commercial farming of pearl oysters (Pinctada maxima and Pinctada margaritifera) and freshwater mussels.
Availability: You can easily buy raw whole shells, traditional solid flat blanks (typically sliced to standard thicknesses like 1.5 mm or 0.06"), dots, strips, and curved pieces.
Varieties: High-grade commercial suppliers regularly stock White, Gold, and Black Lip MOP.
2. Abalone Shell (Haliotis)
Abalone is much more tightly regulated due to severe overfishing, poaching, and disease (such as withering syndrome) affecting wild populations.
Sourcing Restrictions: In many regions, the commercial sale of wild-harvested abalone shell is strictly illegal or limited to strictly monitored, quota-based commercial fisheries. Consequently, most legally sold modern abalone comes from commercial farming operations (aquaculture) or specific sustainably managed fisheries.
Species Differences:
Paua (Haliotis iris): This highly iridescent, deep-blue and green abalone from New Zealand is legally available, harvested under New Zealand’s strict Quota Management System.
Green & Red Abalone: Available from licensed commercial suppliers, but domestic and international shipping often requires strict compliance with wildlife trade regulations. For instance, some US suppliers will only ship certain abalone blanks domestically to ensure compliance with fish and wildlife laws.
Modern Commercial Formats
Because solid, thick blanks from large shells are increasingly expensive and rare, the commercial market relies heavily on engineered shell alternatives alongside traditional solid options:
Solid Blanks: Traditional 1.5 mm thick flat rectangles sold by weight (ounce) or piece, prized for deep, three-dimensional chatoyancy.
Laminated Veneers (e.g., Abalam / Ablam): A massive technological shift in the industry. Micro-thin layers of shell are sliced and layered together with epoxy into larger sheets (5.5"×9.5", for example). This maximizes the yield of the raw material, reduces waste, and makes large-scale CNC cutting far easier and more cost-effective.
Flex Veneers: Ultra-thin shell layers with an adhesive or fabric backing, designed to bend around tight radii or curves without fracturing.
A Note on Shipping & Compliance (CITES and USFWS)
If you are buying or selling these materials commercially across international borders, you must navigate CITES (Convention on International Trade in Endangered Species) and local regulations like the U.S. Fish and Wildlife Service (USFWS). While most common commercial pearl oysters and farmed abalone are not on the CITES endangered list, importing or exporting them still often requires specific wildlife declaration forms, permits, and inspection fees. Most major luthiery and inlay supply houses handle these clearances upstream or specify border restrictions on their catalog items.
Dying your own veneers for purfling lines
Here are two useful resources:
1- Basic veneer dying steps:
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Use a light fast salt-based fabric dye such as RIT or Dharma. Powder, not liquid.
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Mix this with distilled water.
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Put the veneer in a pan big enough to allow the veneer float freely.
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Heat the pan between 160-180 deg until color has completely penetrated.
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This could be several hours.
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Check for penetration by feather cutting the wood.
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Use a light wood such as maple or anigre.
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After full penetration, wash off the veneer with cold water to to "Fix" the color.
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Wipe off and dry between cauls, changing paper to dry the veneer.
2- Some advanced technique:
From the “Cabinet-Maker’s Guide to the Entire Construction of Cabinet-Work” (The Technical Press Ltd., London, 1937) by Richard Bitmead. Bitmead was a professional London cabinetmaker with 25 years experience when he wrote this book. He covered the topic in this short but intriguing entry:
"In the process of dyeing woods throughout their mass, the Parisian veneer merchants have led the monopoly of Europe for a number of years. Veneers or boards dyed through their entire mass of exactly the same colour throughout could not be produced except in Paris. There are a number of English woods which will take the dye and look as brilliant as any woods from France.
In selecting wood for dyeing, for every colour except black, white wood should be used, such as sycamore, beech, lime, &c. If a coloured wood be used, it neutralizes the tint, and the color will be bad. For black, use pear, cherry, beech, or soft mahogany; any of these woods will take the colours well. The first process the wood should undergo is to boil it in a solution of caustic soda (lye) and water, in the proportions of half a pound of caustic soda to five pints of water; the wood should be boiled in the solution for half an hour, and then allowed to remain in to soak for twenty-four hours. It should then be taken out and wiped well with clean deal shavings, to remove the alkali, when it will be found to have become as soft as leather and equally plastic. Then place it between boards, and put weights on the top to flatten, and let remain until dry. This treatment with caustic soda effects a clearing of the pores of the wood from all the gummy or resinous matter, and the open pores, when dry, will absorb the dye-stuffs like a sponge."
EDITOR'S NOTE:Boiling wood veneers in a caustic soda (sodium hydroxide/lye) solution is an effective way to soften lignin or chemically alter the wood, but it introduces significant chemical and thermal hazards. Because you are dealing with a strong base at elevated temperatures, the risks are substantially higher than working with lye at room temperature.