Himik: Oh yeah, let’s break it down like a lab! Those little sticky labels are usually made from a pressure‑activated adhesive—think of a polymer like a soft rubber that’s been tackified with a bit of oil. When you squeeze it onto a surface, the pressure forces the polymer chains to interlock with the tiny pores on the cardboard or tape, making a strong bond that can’t be peeled off until you drop the label. That’s why the tape is super slick at first but then sticks tight once it’s pressed in. Now, the signing part is more about paperwork than chemistry. The receipt is basically a receipt of ownership transfer. By signing, you’re acknowledging that the package was received, you’re giving the company legal proof that the goods were handed over. If something’s damaged or missing, the signature is your first line of defense against a bad claim. It’s like the final calibration step after the experiment—makes sure everything’s on record and you’re not losing your spot on the results sheet. So, in short: the adhesive holds the label in place, and the signature seals the legal contract. Lab done, paperwork complete!