A California man will soon begin the painstaking process of replicating an embossed glass panel that was shattered during an act of vandalism at Iolani Palace last month.

Patrick Mackle, who has reproduced three panes of glass for the palace already, will craft the piece at his shop in Monrovia, Calif. The artwork, which is in a style similar to rococo, a florid style that originated in Europe, has fine brushstrokes that reveal shadows and shapes, he said.

The job will take about three months.

Palace officials said replacing the glass will cost between $14,000 and $15,000, including shipping. A private donor may cover the expense.

The glass was broken on Feb. 8 when two people forced their way into the palace. Police arrested a 30-year-old man and a 21-year-old woman on suspicion of criminal property damage, but released them pending investigation.

Palace officials said it appears a kick broke the glass and opened the door. The glass fractured, but a sheet of tint kept the shards from falling out of the frame. Officials removed the glass and covered the hole with a piece of wood.

Mackle, 63, said he will use the original process employed to create the ornamentation. It is the only way to re-create the original design, which includes a water bird, foliage and a frog. He said the technique is becoming obsolete in today’s use of computerized images with sharp and clean designs.

"You can see the artist’s hand strokes and the brush strokes," he said by phone from his shop. "This is almost like a painting where you actually see where each stroke was laid down."

The reason for the high cost is the quality of materials, the time to do the work and the use of obsolete ingredients, which he happened to stockpile.

Mackle said the palace is sending him the roughly 4-foot-by-1-foot pane, which he plans to study to capture every brush stroke

Besides the craftsmanship, the quality of the glass is important. The original crown glass came from Chance Brothers, a pre-eminent glassworks company in England when the palace was built.

Mackle said a lower-quality glass may have a visible green tint. To obtain high-quality glass, he has to order it from Europe.

Meanwhile, the case against the duo is being investigated by the state Attorney General’s Office. Supervising Deputy Attorney General Christopher Young said the case is a priority because the palace is a national treasure.

He said the office is still deciding whether to bring charges and is awaiting a damage estimate, which will help determine the offense. If the office moves forward with prosecution, it will bring the case before a grand jury, which will decide whether to issue an indictment.

If the pair is charged, an arrest warrant will be issued, Young said.

Michael Juen, the collections manager at the palace, said the pane that was broken in last month’s incident was an original in the Ewa set of doors on the makai side. The palace has six sets of double doors, three on the makai side and three on the mauka side.

Three other panes previously had been broken and replaced. There are 26 embossed panes remaining from when the home for Hawaii’s monarchs was built in the early 1880s.

"These were the ones that were here when Kalakaua and Liliuokalani and Kapiolani were walking the halls and using these doors," Juen said. "You can’t get that history back."

In 1984, a 33-year-old man kicked in two lower panes in the central set of makai doors. In 1991, another man smashed one of the same glass panes replaced after 1984. A third glass pane on the mauka side is a sandblasted replica believed to have been installed around World War II, Juen said.

It cost $15,000 and took three years to replace the two panes broken in 1984, Juen said. According to news reports at the time, another artist tried to replace the panes but didn’t finish. It cost $8,000 and took a few months to replace the single pane in 1991

Mackle, who learned his craft in Europe and started his business, Decorative Glass Processes, in 1981, repaired the glass in both cases.

He said the design requires a rare acid-embossed technique in which the artist paints a tarlike substance on glass and using acid to cut away the design, leaving a reverse etching.

"It’s a lost art," he said. "I’m glad I know how to do the work."