What must be visible on tempered glass to confirm its type?

To confirm that glass is tempered, it is essential for it to exhibit a manufacturer's brand name or logo on its surface. This branding is part of the industry standards and regulations governing the manufacture of tempered glass. The presence of the manufacturer’s brand serves as an assurance that the glass has been produced by a legitimate company that adheres to safety certifications and quality control measures for tempered glass products.

While certification labels can provide a level of verification, the manufacturer's brand name is specifically designated for this purpose and is required by various building codes. This mark indicates that the glass has undergone the appropriate tempering process, which enhances its strength and safety characteristics.

Additionally, it's important to note that specific design patterns and color-coded stickers are not universally required to denote tempered glass, thus making them less reliable as indicators compared to the established presence of the manufacturer's brand name.