Wrappers

Patty-Cake (also known as Clap Hands) 
by Lilly Martin Spencer
A wrapper was typically an informal garment to be worn only at home. A lady might wear it while doing her chores before breakfast. A heavily pregnant or nursing mother might wear it while she is at home with her baby. A woman who was ill might wear it around the house. Only close friends and family were generally allowed to see a lady in her wrapper.

Construction
A wrapper had a smoothly fitted back. The front was generally open to the hem and often only had closures at the bodice and waist. Wrappers generally had belts, either fitted or tassel ties. 

Nearly all wrappers had open sleeves, but there are some exceptions (often in cases where the wrapper is made over from an old dress).

Since wrappers were generally worn at home, wild and crazy fabrics and color combinations were often used. Sometimes a wrapper was made from an old worn-out dress re-purposed with another fabric as the edging. 

Other period names for wrapper were "robe de chambre," "morning dress," "breakfast dress," or "dressing gown."

If a wrapper was left open below the waist, a beautifully trimmed petticoat was often worn to show through the opening.

From The Graceful Lady