In a way, Bob Wojtanoski and his wife Erin are the people on the other side of the looking glass.

Or perhaps better put, they’re the people who give the glass a shine.

As the owners of Sharon Window Cleaning Inc., they oversee a family business that was created before talking movies. Founded in 1918 by Erin’s great-grandfather, the business is among the Shenango Valley’s oldest.

The couple inherited the business from Erin’s mother, Ruth McBride, who passed away last July.

Employing two window washers and another two who work on janitorial services, the business cleans windows of all types –– from commercial to residential.

“Our only limitation now is height,’’ Wojtanoski said. “We do windows up to about 45 feet high.’’

One possibility the company is looking at is buying lifts which would enable workers to clean those high-up windows.

For now though, the company keeps busy with regular accounts and new clients. Contracts with customers can vary from as little as once a year to once a week.

The average price for a home is about $75 to $100.

“The thing is, no two houses are alike,’’ Wojtanoski said. “You have to look at things like the size of the windows, the number of windows and if trees or shrubs are hurting access to get to the windows.’’

During the hot summer months, timing can be a major issue for the cleaning, which is done with squeegees. Windows facing the burning rays of the afternoon sun can’t be cleaned because the water will almost instantly evaporate before cleaning can begin, Wojtanoski said.

One difficult problem that arises for window cleaning is if a home or business recently underwent construction work where concrete was poured nearby. If concrete gets stuck on a window, it must be cleaned very carefully. If it’s removed improperly, the glass will look like it has a small “comet tail’’ because the concrete scraped away glass particles, Wojtanoski said.

New residential customers often think that only the outside needs to be cleaned, he said.

“When we get done with the outside, they see that the window is still dirty,’’ he said. “What they don’t realize is that the inside gets just as dirty. That’s why we usually recommend you get the inside and outside cleaned.’’