PET cold cups are clear and rigid and crack when you squeeze them. PP cold cups are slightly hazy, more flexible, tolerate heat, and are the only one of the two that works with a sealing film machine. If you run boba, smoothies or anything sealed, the answer is PP. For iced coffee and cold brew where the drink is the display, it is usually PET.
Here is the full comparison.
Quick answers
PET. Polyethylene terephthalate. Glass-clear, rigid, brittle. Best clarity of any disposable cold cup. Not for hot liquid. Widely accepted in curbside recycling as resin 1.
PP. Polypropylene. Slight haze, flexible, tolerates warm liquid, takes a sealing film. Resin 5. Recycling acceptance varies by municipality.
Sealing film only works on PP. This is the single decision that overrides all the others.
Both are printed the same way and both need the same food contact documentation.
Clarity
PET wins, and it is not close. A PET cup is optically clear in a way PP cannot match. Layered drinks, cold brew with cream falling through it, fruit suspended in a lemonade: all of that reads better through PET.
PP has a faint milky cast. On a solid-colour drink nobody notices. On a drink whose appeal is that you can see into it, people do.
If your cold menu is photographed for social, and the photograph is the marketing, this matters more than the price difference.
Sealing film
If you seal cups with a film machine, you need PP. PET rims do not bond reliably to standard sealing film, and the cup deforms under the heat of the sealing head.
This rules the decision for anyone running boba, sealed smoothies, or a delivery program where a spill-proof top is the point. There is no clever workaround. Buy PP.
Two things to specify when you order for sealing:
Rim diameter. Your sealing machine has a die sized to a specific rim. 95mm and 98mm are the common ones. The cup, the die and the film all have to agree, and a cup that is 3mm off is a cup you cannot use.
Rim profile. Sealing cups have a flat rim built for the job. A standard drink-lid rim with a rolled curl will not seal well even in the right diameter. Say "for sealing film" in the quote request so you get the right tooling.
Heat
PP handles warm liquid. PET does not.
This sounds irrelevant for a cold cup until you consider what actually goes into one. Hot tea poured over ice for a shaken iced tea. Freshly brewed espresso into an iced latte. Hot syrup. A PET cup can soften, warp or split on contact with any of these before the ice brings the temperature down.
PP has a meaningfully higher service temperature and shrugs this off. If any of your cold drinks start hot, PP removes a whole category of problem.
Durability
PP flexes, PET cracks.
A PET cup dropped into a bag with other orders, or gripped hard by a delivery driver, can split at the base or star-crack down the side. It fails visibly and it fails wet.
PP deforms and comes back. For delivery, catering, events and anywhere a cup gets handled more than twice, PP survives better.
Recycling
Honest answer: both are recyclable in principle and both are contaminated in practice, because a drink cup arrives at the facility with liquid and a straw in it.
PET is resin 1 and is the more widely accepted of the two in North American curbside programs. PP is resin 5 and acceptance is patchier, though it has improved.
If sustainability claims are part of your brand, be careful how you word this. "Recyclable where facilities exist" is defensible. A flat "recyclable" on a cup that most of your customers cannot actually recycle locally is the kind of claim that gets challenged.
Cost
They price close enough that cost is rarely the deciding factor. PP is often marginally cheaper at the same wall thickness, but wall thickness varies more between specs than the resins vary between each other. Ask for both on the same quote if you genuinely have no other constraint.
Printing
Both print the same way and neither takes fine detail as well as paper. Plan for bold marks and generous line weights.
The thing worth knowing is that a printed cold cup is viewed through the drink as much as against it. A design that looks good flat on a screen can disappear against dark cold brew or fight with a bright lemonade. Consider where the artwork sits vertically on the cup, and leave a clear window if you want the drink visible.
Minimums and what to send
Custom printed cold cups run at a minimum of 10,000 per size, same as paper. Per size, not total. Two sizes is 20,000 cups.
To get priced, send:
PP or PET, or say you want both quoted.
Size in ounces and quantity per size.
Rim diameter, and whether it is for sealing film.
Artwork, or a logo and a rough sense of coverage.
Pricing comes back at two quantity breaks, and drops again through 20,000 and 50,000. Quotes land in two business days. Production is 6 to 8 weeks by sea and faster on repeat runs.
Food contact
Both resins used for drink cups fall under the FDA food contact rules in 21 CFR 177. Ask for the documentation before you order, in writing. A supplier who cannot produce it on request is a supplier who will not produce it when a buyer or an inspector asks you for it either.
Where to go next
For the full plastic range and what seals to what, see custom plastic cups. For the paper and plastic ranges side by side, see custom cups.
If you are still working out which sizes to run, custom cup sizes explained covers brim-full volume, rim diameter and why a 16oz cold cup delivers about 11oz of drink once ice is in it.
