The single decision that determines whether a 1 oz sample jar reads as "premium trial size" or "generic giveaway" on an ecommerce private-label unboxing is the label. A 30 ml thick-wall polystyrene jar with a clean curved sidewall, a flat top recess on the white PP cap, and crystal-clear sidewalls that read like glass under a ring light is a label canvas - not a container that needs to be hidden by overwrap. That is the design brief the 28301 was engineered to satisfy.
What the 28301 Actually Is
A 1 oz (30 ml) clear polystyrene (PS) thick-wall jar with a 43 mm continuous-thread neck finish, supplied with a matching white polypropylene (PP) screw cap, no cap liner. Listed at $0.82 per jar with cap included (freight quoted separately to your delivery ZIP via the freight estimator at /freight-cost-estimator/ or by phone). Bisphenol A was not intentionally used in the manufacture of this jar. The thick sidewall geometry gives the jar a heft and optical clarity that is closer to molded glass than to a thin-wall PET cosmetic jar - which is the visual cue that signals "premium sample" rather than "promotional throwaway" when the jar lands in a private-label PDP photo or a subscription unboxing reel.
The Labeling Surface Is the Feature
The cylindrical sidewall of the 28301 measures roughly 1.5 in tall by 1.7 in diameter, giving a wraparound label window of approximately 1.4 in tall by 5.3 in circumference (about 7.4 sq in of decorated surface before wrap-overlap). That dimension fits a standard 1.25 x 4 in pressure-sensitive label off a die-cut roll with clean top and bottom margins, which is what a Shopify or Amazon private-label brand running a tabletop semi-automatic labeler at home or in a 3PL fulfillment bay actually uses. Flat top recess on the cap accepts a 1.25 in diameter top-label or foil seal for the secondary brand mark. Two label positions, two color-runs, one jar - the visual density of a $40 cosmetic SKU sold at the trial size point.
Why Polystyrene, Not PET or PP
PS - polystyrene - is rigid, crystal-clear, and dimensionally stable at room temperature. It holds a wraparound label flat without the slight oval-creep that thin-wall PET shows under shrink-tunnel heat. The trade-off is that PS is brittle to impact: drop a filled PS jar onto a hard tile floor and it can crack at the shoulder, where PET would dent and bounce. For trial-size, sample, and lab-storage applications where the jar lives inside a poly mailer, a kraft sample box, or a retail display tray - none of which subject the jar to a drop - PS is the right resin. For applications that go into a beach bag, a gym duffel, or a checked airline bag, a thicker-wall PP or PET jar is the safer geometry.
Fill and Use Constraints
Polystyrene softens visibly above 180 F and will deform at 200 F. The 28301 is a cold-fill or room-temperature-fill jar. It is the right jar for: anhydrous cosmetic balms, solid sample creams, salt scrubs, dry blends, powder samples, lab specimen storage at ambient or refrigerated temperatures, supplement trial-size capsules, and any non-aggressive cold-fill cosmetic or food trial format. It is the wrong jar for: hot-pour candle wax (PS will deform and stress-crack), aggressive solvent contact (acetone and limonene attack PS), acidic essential oils at high concentration (citrus terpenes can craze PS over time), or any application above 160 F.
Sample Distribution Math for a Private-Label Brand
A direct-to-consumer cosmetic or supplement brand running a "free trial with first order" promotion typically ships the 1 oz trial in a 6 x 4 x 2 in kraft poly-mailer at USPS Ground Advantage rate. Per-jar landed cost at 1,000-unit run: roughly $0.82 for the jar with cap, $0.18-0.25 for a custom-printed pressure-sensitive label, $0.08-0.12 for the kraft mailer, and $4.10-4.95 for postage on a single-jar shipment - which puts the trial-size shipment total between $5.30 and $6.20 before the product fill, with freight as a meaningful share of that number. That math is what makes the 1 oz trial format viable as a CAC line item: it is small enough to ship inside a poly-mailer instead of a corrugated box, which is the cost discontinuity that determines unit economics on a trial-size sample program.
Order Quantities and Stocking
The 28301 ships in case-pack increments suitable for a 100-unit, 500-unit, or 1,000-unit private-label sample run. For brands ramping past 5,000 trial jars per month, full-pallet purchasing is available - the per-jar list price holds, and freight class drops from LTL parcel to pallet rate, which is the inflection point where the trial-size sample stops costing the brand margin and starts contributing to per-customer margin.
Custom Decoration Beyond Labels
For runs of 5,000 jars or more per color, direct silk-screen printing on the jar sidewall is available - one color, two colors, or full-wrap process color. Hot-stamp foil application on the flat top recess of the white PP cap is available for runs of 2,500 caps per stamp design. Shrink-sleeve full-body labels are also available for SKUs where the brand wants the jar itself to read as a custom-tooled mold without the $18,000 mold-tool capital spend. Call 866-418-1777 to set up artwork review, sample proof, and per-piece pricing on any decoration path. The same call also covers case-pack quantity, freight class to your delivery ZIP, and lead time on current warehouse inventory of the 28301.
FAQ
What is included with the 28301 - is the cap separate?
The cap is included. Each 28301 jar ships with a matching white polypropylene (PP) continuous-thread screw cap, no cap liner. List price reflects the jar plus cap as a single unit. If your formulation needs a foam liner, foil induction seal, or pressure-sensitive liner, those are available as add-on cap upgrades - call 866-418-1777 to specify.
What is the maximum fill temperature for the polystyrene jar?
Cold fill or room-temperature fill only. Polystyrene softens visibly above 180 F and deforms at 200 F. The 28301 is suitable for anhydrous balms, salt scrubs, dry blends, powder samples, lab specimens, and any non-aggressive cold-fill cosmetic or food trial format. It is not suitable for hot-pour candle wax, hot-fill food, or any application above 160 F.
What size pressure-sensitive label fits the sidewall?
The cylindrical sidewall accepts a wraparound pressure-sensitive label up to roughly 1.4 in tall by 5.3 in circumference - approximately 7.4 sq in of decorated surface before wrap-overlap. A standard 1.25 x 4 in die-cut PS label off a roll fits with clean top and bottom margins on a tabletop semi-automatic labeler. The flat top recess on the white PP cap accepts a separate 1.25 in diameter top-label or foil seal for a secondary brand mark.
Is the 28301 BPA-free and what is the regulatory profile?
Bisphenol A was not intentionally used in the manufacture of this jar. Polystyrene is permitted for food contact under 21 CFR 177.1640 and the matching PP cap is permitted under 21 CFR 177.1520 - the standard FDA regulations covering these resins for food and cosmetic contact applications. For regulated content (OTC drug, infant product, dietary supplement requiring specific compliance documentation) confirm full documentation requirements with your formulator and our team before scaling production.
Can the jars be custom silk-screened or hot-stamped with my brand?
Yes. Direct silk-screen printing on the jar sidewall is available for production runs of 5,000+ per color - one color, two colors, or full-wrap process color. Hot-stamp foil application on the flat top recess of the white PP cap is available for runs of 2,500 caps per stamp design. Shrink-sleeve full-body labels are also available for SKUs where the brand wants the jar itself to read as a custom-tooled mold without the capital spend on a custom mold.
What is the case pack quantity and minimum order?
Standard case-pack increments support 100-unit, 500-unit, and 1,000-unit private-label sample runs. For brands ramping past 5,000 trial jars per month, full-pallet purchasing is available at LTL freight rates, which is the inflection point where freight class drops from parcel to pallet rate. Call 866-418-1777 to confirm current case-pack quantity, lead time, and pallet pricing.
How is freight quoted on the 28301?
List price is per-unit (jar plus cap). LTL freight is quoted separately to your delivery ZIP through our freight estimator at /freight-cost-estimator/ or by phone at 866-418-1777. Pallet rate, residential delivery surcharge, and lift-gate are quoted at the same time. We do not bundle freight into the jar list price.
Sources cited: FDA 21 CFR 177.1640 (polystyrene food-contact regulation), FDA 21 CFR 177.1520 (polypropylene food-contact regulation), OneSource Plastics 28301 technical specification
