A sticky handle or flaking surface is a reason to inspect the material and finish. It is not enough evidence to identify the entire bag as genuine leather or synthetic.
Separate the surface from the base
A coated textile has a fabric backing and a surface coating. Leather can also have a protective or decorative finish. The failure of a finish does not by itself identify the substrate.
Surface and substrate are different layers
Coated textile
Top: coating. Below: textile backing. Some constructions also use an adhesive layer.
Finished leather
Top: an optional applied finish. Below: the leather fibre structure. Unfinished leather has a different surface.
Some polyurethane formulations are vulnerable to hydrolysis. Heat and moisture can accelerate deterioration, but there is no single humidity threshold or lifespan that applies to every coated material. Abrasion, flexing, cleaning products and adhesion failures can also contribute to surface damage.
Inspect without damaging the piece
Read the material description and ask what it says about the backing, finish and care. A visible cut edge may offer clues, but a hidden edge or a coating can obscure the construction.
Do not use water absorption as a definitive authenticity test. Finishes affect absorption, and a test drop can mark some surfaces. A crease pattern or smell alone is also insufficient to certify material identity.
Request the material and finish used for the particular piece. A broad label such as genuine leather or synthetic does not establish durability or water resistance.
Respond to peeling
Stop applying unrelated cleaners or oils to a peeling area. Photograph the damage and ask the maker about the finish and suitable repair options. Conditioner cannot rebuild a failed coating.
Store a clean, dry piece with ventilation and avoid prolonged heat or damp. Care depends on the finish and construction. See the Canadian Conservation Institute’s overview of leather deterioration for background; its treatment advice concerns collections rather than routine conditioning of everyday bags.
Ask about a material or finish