Glass bottle, boston round, black glossy, 100 ml

Glass bottle, black glossy dropper bottle, 100 ml — shields the contents from light. It is an opaque glass container for cosmetics and foods that are sensitive to light. Black glass is practically impermeable to light, making it ideal for face and body oils, serums, tinctures, drops, tonics and extracts with ingredients susceptible to photo-oxidation.

The neck has an 18/410 thread, so the bottle can be closed with a cap, dropper, pump or spray with the same neck type. The container is approved for direct contact with food, making it suitable for homemade herbal oils, syrups, infusions and concentrates.

Why choose black glass

• Light protection – amber or blue glass only reduces light transmission; black glass is fully opaque. Oils rich in unsaturated fatty acids, vitamin serums, retinoids and plant extracts therefore degrade more slowly.
• Chemical stability of glass – glass does not react with essential oils, alcohol or solvents, leaches nothing into the contents and does not absorb odours. Suitable for aqueous, alcoholic and oil-based fills.
• Consistent product appearance – the colour of the contents is not visible, so a product range with differently coloured fills looks uniform on the shelf. The glossy surface holds labels and direct printing well.
• Reusability – glass can be thoroughly washed, disinfected and refilled without any loss of performance.

Nominal and total volume

The bottle is designed to be filled with 100 ml, which is its nominal volume. The total volume to the rim is slightly larger and represents the physical capacity up to the neck. The difference between the two values is the headspace taken up by a dropper or pump inserted into the neck and needed for the contents to expand with temperature changes. The bottle should therefore be filled to the nominal volume, not to the brim. Filling to the brim risks overflow when fitting the closure and creates pressure on the seal.

Closures and combinations

Closures with an 18/410 neck and ready-made combinations of the bottle with a dropper, pump or spray are available in the Handymade range. With a custom combination, we recommend verifying the seal integrity, dosing behaviour and compatibility of the container with the specific formulation. This applies in particular to alcoholic and very thin fills, which leak more easily when the bottle is inverted.

What to know when working with this container

• Preparation before first fill – wash the bottle, rinse it with isopropyl alcohol or ethanol and allow to dry completely neck down. Residual water in an oil-based or anhydrous product promotes microbial growth.
• Filling temperature – glass can withstand hot filling, but a sudden thermal shock between cold glass and a hot product may cause cracking. Before hot filling, allow the bottles to warm to room temperature or temper them gradually.
• Monitoring contents – black glass makes it impossible to see the fill level or changes in the product, such as cloudiness, phase separation or sediment. When working with your own formulations, keep a reference sample in a clear bottle of the same volume.
• Labelling – the smooth, glossy surface takes self-adhesive labels well. On a dark background, light-coloured, metallic or transparent labels with light printing are the most legible.
• Recycling – the packaging is made from a single material; once the closure is removed, it belongs in the glass recycling bin.

Frequently asked questions