Portland artist Eric Franklin spent over 1,000 hours sweating over hot glass and noble gasses to produce Embodiment, a glass skeleton filled with glowing krypton.
Speaking about the process, Eric says:
Every glass seal has to be perfect, and this piece contains hundreds. Everywhere one tube joins another, or a tube terminates, glass tubes were sealed together. They have to be perfect in order to preserve the luminosity of the krypton. If one rogue molecule gets inside the void of the glass tubing it can eventually contaminate the gas and it will no longer glow. There are times when the holes in the seals are so small that you cannot actually see them with your eyes without the help of a leak detector. Once the glass pieces are ready to get filled with gas, I pull a high vacuum while the glass is hot in order to evacuate any dust or water vapor from the interior surface until there are literally no molecules inside the void of the glass. Then the krypton can be introduced and the glass sealed off. It's an extremely tedious process, one I have somewhat of a love/hate relationship with.
Be sure to check out Christopher Jobson's website Colossal for the full details.