Mother of pearl or nacre is a processed shell product. It produces a lovely, high quality button with a pleasant lustre. It can be quite light coloured, or much more richly toned with a transparent, luminescent quality. Old mother of pearl buttons may be somewhat discoloured; however, you can clean and care for these buttons as you would other shell materials, depending upon their value and condition. Bleaching mother of pearl buttons requires peroxide as a bleaching agent, rather than chlorine.
Wipe the mother of pearl buttons with a soft cloth dampened with mineral oil to clean the MOP buttons before bleaching. Remove all visible dirt and residue to achieve even colour lightening in the peroxide based MOP bleaching solution. Check the colour of the MOP buttons and look for staining or discolouration that may be improved by bleaching.
Make a solution of 3 per cent hydrogen peroxide to bleach mother of pearl buttons in a small, non-reactive dish. Place the MOP buttons into the solution. Allow your mother of pearl buttons to soak until the desired level of colour lift is achieved.
Remove the MOP buttons from the peroxide bleach solution and wipe with a damp cloth. Dry well, using a hair dryer on low if necessary. Polish with mineral oil on a soft cloth.
Use your mother of pearl buttons as they are now with their new bleached colour or acid dye them after bleaching to coordinate them with fabrics or supplies for a craft project.
Assess the condition and value of your mother of pearl buttons. Clean valuable MOP buttons with care, but do not attempt to bleach old MOP buttons with financial or sentimental value. Check the percentage of peroxide in the hydrogen peroxide solution you use. Three to 5 per cent is ideal, but you can experiment with a peroxide bleach solution of up to 10 per cent.
Avoid bleaching buttons with metal shanks or hardware. Never use chlorine bleach on mother of pearl.