11. Another treatment, which has become more frequent in recent years, is lead glass filling. 12. Lead glass , which is especially suitable for optical instruments, caused English glassmaking to prosper.13. For example, lead glass bonds readily to copper or molybdenum, but not to aluminum. 14. The gold tone was drawn from the amber lead glass windows in the top doors. 15. This refers to lead glass as " Jewish glass ", perhaps indicating its transmission to Europe. 16. The ingredients used to make the glass were lower-cost than those used to make lead glass . 17. Several textual sources describing lead glass survive. 18. Although little is known about these materials, it does suggest that lead glass contributed to England's exports. 19. For more details, see lead glass . 20. The glass is usually lead glass .
