Devardi Glass Lampwork, Beadmaking Roller/Rounding Graphite Marver Devardi Glass Lampwork Graphite Marver, Roller/Round Shaper High Quality Graphite Marver. Make rounded or square shapes easily with this great marver. 2 x 3 inches with a strong steel hand and rubbery plastic grip. Please click the blue "Devardi Glass" above to see all our listings.