GALVESTON — Trinity Episcopal Church is planning to restore its Tiffany windows.

The church’s stained-glass windows, which were commissioned in memory of George Sealy by his wife, Magnolia, are by famed artist Louis Tiffany.

Frances Newell, great-granddaughter of Magnolia Sealy and granddaughter of Ella Sealy, said the windows at Trinity are not just about the Sealy family.

“Those windows were put in right after The Great Storm destroyed everything in Galveston,” she said. “Those windows are a story of renewal and triumph, coming back after the storm. They are a masterpiece. Restoring those windows is as important as restoring a Monet painting — it’s in that league.”

Newell has written an eight-page booklet that illustrates Tiffany’s glass-making techniques.

“Tiffany wanted stained glass to be 3-D, alive with color, and he wanted the glass itself to be an expressive medium,” she said. “He did the most to maximize the light. He made glass with a lot of textures, making it iridescent by adding metallic oxides.”

She said he used the metallic oxides to make waves and swirls in the glass, and got the texture and color directly into the glass.

“He was also famous for experimenting with light,” Newell said. “He always wanted to see how the light passed through the glass at different times of the day. He wanted every moment to be a good moment to photograph it, not just wait till the light hit the glass just right to do the photograph.”

Her booklet explains how Tiffany also used a dangerous but effective technique using hydrochloric acid to etch the finest details into the glass.

“He melted a wax mold, etched fine lines such as cheekbones or the hairs on Jesus’ head onto it, and then dipped the whole glass into acid,” she said. “The acid would eat away where there wasn’t any wax. This is how you can see those very fine details. Etching is very effective, but it’s terribly dangerous.”

The most acute problem that has put the Sealy windows in jeopardy is that the fragile stained glass, soldered together by metal, have seen more than a century of weather extremes. Metal and glass react differently to heat, humidity and cold.

“Many parts of the windows are actually layered, which is another of Tiffany’s amazing techniques,” Newell said. “In some places, there are as many as eight layers of stained glass. Each layer needs to be carefully cleaned and reinforced. I just want everyone to know how special these windows are and to come and take a closer look and realize how important it is to preserve it.”

She also said that she believed the windows were a living, breathing, moving piece of art. “It’s always changing because of the light,” she said. “It literally floats. It’s a live piece of history.”

Newell’s booklet about Tiffany’s stained-glassmaking techniques and the Sealy altar windows are available at Trinity Episcopal Church, located at 2216 Ball Ave.