Why do most Bangkok laundries charge by weight instead of by item?
Weighing is faster and removes argument over what counts as a 'piece'. Counting items means staff stop to debate whether a t-shirt and an undershirt are one piece or two, whether socks are paired or solo, whether a pillowcase counts. Weighing is one number, agreed once. Most Bangkok premium services charge a single per-kg rate (160–220 THB / kg) that covers wash, dry, fold and standard packaging. Item-based pricing only appears for dry-cleaning specialty pieces (suits, wedding dresses), where the labour per piece varies wildly.