Crushed glass, deep color, and a finish that catches the light. Compare every smalt listing in Letterhead Sign Supply’s catalog, then plan the job by coverage and grain size.
Letterhead describes smalting as the practice of embedding colored glass aggregate into a heavy paint-and-medium bed to make a long-lasting, textured sign background.
Glass smalt carries its color inside the glass. Transparent grains let light travel through the field, giving painted and gilded lettering a sparkling, dimensional ground.
The technique became especially popular from 1865–1935 and remains useful for full backgrounds, borders, and selective accents. Standard colors below are 1-pound bags of medium 1–2.4 mm pieces unless the card says otherwise.
All product photographs, color names, sizes, and outgoing links come from Letterhead Sign Supply. Deep Red stays in the chart for reference but is marked unavailable.
A concise version of Letterhead’s smalting tutorial. Always make a test panel; temperature and season can change working and cure times.
Prepare a clean, dry panel and mask the exact area to receive smalt.
Combine smalt cream and matching oil-based lettering enamel 50/50.
Lay down a heavy, even coat and allow about 30 minutes for it to settle.
Apply lightly and repeatedly. Early passes sink; later passes build an even surface.
Wait until fully cured before lifting the panel and returning loose grain to a container.
Product details and photographs were collected from Letterhead Sign Supply on September 24, 2026. Listing status can change; use each card’s product link for the latest purchase information.