Exterior and shape
Inspect all four corners, base piping, handles, seams and side panels. Compare the bag's silhouette with a reference image for that model and size. Creasing may be normal use; collapse, severe warping or uneven shape may suggest poor storage or a structural issue.
Material and colour
Ask whether the leather has been cleaned, recoloured, conditioned or refinished. Check for colour transfer, water rings, dryness, cracking, sticky coatings and strong odour. Canvas, coated surfaces, suede and exotic materials need different checks and care; use a specialist for unfamiliar finishes.
Interior, hardware and function
Open every pocket and check lining seams, stains, pen marks, powder, odour and hidden corners. Test zips, clasps, feet and strap attachments gently. Look for plating loss, corrosion and replaced hardware; request close-ups rather than relying on a single overall condition grade.
Repairs and total cost
Ask for receipts and the name of the repairer for every repair or replacement. Add authentication, cleaning, shipping, tax and possible repair to the asking price. If a defect is not visible in the seller's photos or is not disclosed in writing, do not assume it is insignificant.