Tees are the easiest thing to get wrong on size because a single letter hides a huge range of cuts, so always read the flat measurement chart and compare it to a shirt you already wear. Oopbuy takes no service fee, which makes tees a low-cost way to test a seller's quality before committing to pricier pieces from the same maker.
Start with the three numbers that define a tee's fit: chest (pit-to-pit), full length from the high shoulder, and shoulder width. A modern "boxy" or streetwear tee is deliberately wide and short; a classic cut is longer and slimmer. Knowing which you want stops you from sizing up on an already-oversized pattern and ending up with a tunic.
Fabric weight changes everything about how a tee looks and lasts:
Because cotton tees shrink, plan for it. A cotton-heavy shirt can lose length on a hot wash, so if you are on the border between sizes, size up and wash cold. Fabric with a little elastane holds its measurements better and can be ordered closer to your exact size.
For graphic and printed tees, the QC photos are where you protect your order. Check that:
Tees are light and pack flat, so they are the ideal filler when consolidating a larger Oopbuy shipment; the marginal freight cost per shirt is small. Even so, don't over-order a size you haven't verified. For live shipping estimates, item pricing, and any active promotions, check the current Oopbuy listing rather than relying on older numbers. Buy one, confirm the fit and print, then repeat the size that worked.