From The Assembly Line:
The Lab coat is a workwear inspired coat with a mid-length style. Features a hidden button front, a clean round neck and large patch pockets for added functionality.
Depending on which look you want there are many suitable fabric choices.
To have the workwear touch suggested fabrics are heavy weight fabric, such as canvas, twill, panama, denim, corduroy.
For a dress-like version choose a light to mid weight fabric such as linen, denim, cotton twill, wool, lightweight canvas. Perhaps skip the hidden button front and choose visible buttons and no lower pockets. Or if you’re looking for an even softer variant, more like a cardigan or kaftan, choose a light weight fabric, visible buttons and no pockets.