Larger | Spin | 3D. Indium foil. Indium is often used to form air-tight seals between glass components because it is soft enough to mold itself to the shape of the glass, and because unlike rubber or other organic seal materials it is really 100% gas-tight and it doesn't release volatile compounds of its own.
Melasma is a chronic skin disorder that results in symmetrical, blotchy, brownish facial pigmentation. It can lead to considerable embarrassment and distress. This form of facial pigmentation is sometimes called chloasma, but as this means green skin, the term melasma (brown skin) is preferred.
For people with melasma, a history of skin cancer, or very fair skin: For patients with a blotchy brown discoloration of the skin called melasma, those who have had skin cancer, or those who are very fair, sunscreen with an SPF of 30+ is recommended daily for extra protection.