The signature up-Island confectionery that is a Vineyard institution its own right, will close at the end of the year, the owners have said.

A letter went out to employees this week from owners Mary Beth Grady and Allison Burger informing them that they will close the store in December.

The letter is posted in the store, which recently reopened for Valentine’s Day.

“We are hanging up our aprons and gloves. We feel very fortunate to have had a chance to work with all of you and so many other inspiring people over the past 33 years,” it says in part.

The letter quotes Mother Teresa and also says the business will not be sold.

The business model for Chilmark Chocolates, which produces high-quality handmade chocolates and candy, is unique and includes training and employment for people with disabilities. The owners met when they were counselors at Camp Jabberwocky more than 30 years ago, and later became employees and then owners at Chilmark Chocolates.

“We feel it is important that people have a chance to reach their potential,” Ms. Grady said when she and her partner were honored as women of the year in 2015 by Women Empowered, an Island business group. “People with disabilities work side by side with others, and team members, each person doing what he or she is able. Work reminds us of our value.”

Despite the store’s wild popularity among summer and year-round residents alike, the store’s owners have never expanded and have followed a schedule that includes closing in August and at other times during the year.

The owners have also had a long policy of granting no interviews and allowing no press.