Cardinal Glass Industries
Cardinal is one of the few major producers that both manufactures its own float glass and fabricates finished insulating glass units in-house, rather than selling raw glass to independent fabricators.
Company background
Cardinal Glass Industries was founded in 1962 and remains privately held, headquartered in Eden Prairie, Minnesota. Where many competitors split into separate float-glass manufacturers and downstream fabricators, Cardinal runs both ends: it melts and floats its own glass, applies its own Low-E coatings, and assembles the finished insulating glass units that go into windows, all within its own network of plants.
That vertical integration is the main thing worth knowing about Cardinal as a company; it is also why Cardinal-coated glass is harder to buy loose, it tends to arrive already fabricated into a window manufacturer's finished IGU.
Product lines you'll see in specs
Cardinal's Low-E coatings are branded LoĒ (read "low-E"), numbered by generation and silver-layer count. The numbers roughly track how much they prioritize solar control over visible light.