SALEM, N.H., Oct. 5 -- Andover Corp., a manufacturer of optical interference filters and optical coatings for the electro-optics and biomedical markets, announced that it now offers on-line buying on its Web site, www.andcorp.com. As part of its strategy to increase ease and convenience of ordering, Andover has made all of its standard products -- about 60% of its total product line -- available on-line, accepting payment by credit card and shipping via UPS (domestically) or International Express Mail. The company also produces such specialty items as precision image quality and ultranarrow bandwidth filters.According to William E. Grenier, Andover's vice president of marketing and sales, the move to e-commerce will reduce costs for customers placing low-volume orders and simplify after-hours and international ordering. Grenier said the company sees e-commerce complementing traditional ordering methods such as purchase orders, which allow customers to control and monitor large-volume shipments easily.