Plastic Bottle Caps

Wholesale plastic bottle caps for small businesses and makers who need a reliable seal every time. Available in black and white, these PP caps fit a range of glass bottle sizes — from your smallest 10 ml vials up to full 16 oz Boston rounds.

Compatible with our glass bottles, including Boston round, syrup, packer, and euro bottle styles. If you need a cap that pairs with our 10 ml roll-on bottles, we've got those covered too.

Boston Round and Packer Bottle Caps

Boston round and packer bottles are workhorses — used for oils, serums, tinctures, supplements, and anything that needs a clean, secure screw top. These caps thread on consistently and hold through shipping. No fussing with fit.

Syrup and Euro Bottle Caps

Syrup and euro bottle styles have their own neck specs, and these caps are sized to match. Whether you're filling cocktail mixers, herbal syrups, or apothecary blends, a cap that fits properly is just the start — the Polycone liner does the real sealing work.

Browse the full range of closures at Caps & Closures.

What Makes These Caps Work

Polypropylene (PP) is the right material for screw caps. It's rigid enough to thread cleanly, light enough not to add unnecessary weight, and chemically stable across a wide range of contents — oils, water-based formulas, alcohol-based products, and more.

The Polycone liner is what gives you the actual seal. It compresses against the bottle neck as you tighten, filling any small gaps and preventing leaks in transit. That matters when you're shipping a hundred units at a time and can't afford returns from leaky bottles.

Available in classic black and white — both finish clean on the shelf and don't fight your label design.

Who These Caps Are For

Plastic bottle caps aren't a one-industry product. Here's who typically orders from this collection:

• Skincare and cosmetics brands — face oils, serums, toners, body oils in Boston round and packer bottles
• Herbal and supplement makers — tinctures, liquid extracts, and supplements in Boston round styles
• Food and beverage producers — cocktail syrups, hot sauces, and specialty liquids in syrup bottles (verify compatibility for your specific application)
• Candle and home fragrance makers — fragrance oils and blending supplies in Boston round and euro styles
• Apothecary and wellness brands — blended oils and topical formulas in packer and euro bottles
• Private label companies — building consistent SKUs across multiple bottle formats
• DIY makers and small-batch producers — anyone who needs a tight, clean seal without buying in industrial quantities

Frequently Asked Questions

What sizes do these plastic bottle caps fit? These caps are compatible with glass bottles from 0.5 oz up to 16 oz. Fit depends on neck finish — standard sizes like 18-400, 20-400, 24-400, and 28-400 are the most common across our Boston round, packer, syrup, and euro bottle collections. Check the individual product listings for exact neck finish specs before ordering.

What's a Polycone liner and why does it matter? A Polycone liner is a cone-shaped plastic insert inside the cap that compresses against the bottle neck when the cap is tightened. It creates a snug, leak-resistant seal without requiring a separate foam or cardboard liner. For liquid products especially, it's the difference between a cap that holds and one that seeps.

Are these caps compatible with both glass and plastic bottles? These caps are sized to fit The Bottle Depot's glass bottle range. PP caps are generally compatible with glass bottles across the common neck finishes. If you're fitting them to a different manufacturer's bottles, confirm the neck finish measurement before ordering.

Do the caps come in colors other than black and white? Currently available in black and white. Both are versatile enough to work with most label and branding setups. If you're after a specific color, reach out and we can advise on availability.

What's the minimum order? No high minimums. You can order in small quantities to test fit and look before scaling up. Pricing adjusts as quantities increase.

How fast do orders ship? Orders ship within 3–5 business days to anywhere in the USA. Over 5,000 customers have ordered from The Bottle Depot since 2018 — fast, reliable shipping is part of how we keep them.

What if the caps don't work for my bottles? We stand behind our products. If something doesn't fit or doesn't perform as expected, get in touch and we'll sort it out. Satisfaction is backed by our refund guarantee.