Why the Karen and Lucy 30cl Candle Glass Remains So Popular

If you spend any time in the UK candle-making community, one size comes up again and again: the 30cl candle glass. It is, by a comfortable margin, the most popular vessel size for both hobbyist makers and professional brands alike. And within that category, two designs from Colorlites have become genuine industry standards — the Karen and the Lucy. Whether you are pouring your very first candle at the kitchen table or running a large-scale production line supplying high-street retailers, these glasses offer the perfect combination of form, function, and value. In this post, we explain exactly why the Karen and Lucy 30cl candle glasses remain so popular, break down their technical specifications, compare the two designs, and help you choose the right glass — and the right lid — for your brand.

The Karen and Lucy: Design Heritage

The Karen and Lucy are part of Colorlites' signature glassware range — a collection of candle vessels designed specifically for the craft and professional candle-making market. Both feature a clean, contemporary tumbler design that looks equally at home in a minimalist Scandinavian-inspired brand as it does in a traditional English country house collection. That versatility is one of their greatest strengths: whatever aesthetic your label is aiming for, the Karen and Lucy provide a canvas that works.

These glasses have been available for well over a decade, and in that time they have earned the trust of thousands of UK candle businesses — from sole traders selling at craft fairs to established brands stocked nationally. The 30cl size hits a genuine sweet spot in the market. At 300ml capacity, the glass is large enough to deliver a meaningful burn time of 35 to 45 hours depending on wax type and wick choice, yet compact enough to feel elegant, giftable, and appropriately priced for the consumer. It is no coincidence that many of the candles you see on the shelves of independent boutiques across Britain sit in a 30cl vessel.

Technical Specifications

Understanding the technical details of your candle glass matters — it affects everything from wick selection to lid fit to shipping weight. Here are the key specifications for the 30cl Karen and Lucy:

• Capacity: 30cl (300ml) — the UK's most popular candle vessel size
• Glass type: Soda-lime glass, the industry standard for candle containers, offering excellent clarity and durability
• Wall thickness: Engineered for even heat distribution during burning, reducing the risk of hot spots and ensuring a consistent melt pool
• Neck diameter: Compatible with standard candle-making wicks and wick holders, making it easy to work with regardless of your preferred wick supplier
• Heat resistance: Rated for safe candle burning across all common wax types, including higher melt-point paraffin blends
• Weight: Sturdy enough to feel premium in the hand, yet light enough to keep shipping costs manageable for e-commerce brands
• Thread finish: GL thread on the neck, providing secure and consistent compatibility with Colorlites' full range of 30cl lids

These specifications mean that whether you are following our Ultimate Candle Making Guide for your first pour or scaling up an established production process, the Karen and Lucy glasses perform reliably and consistently.

Karen vs Lucy: What's the Difference?

This is one of the most common questions we are asked, so let us break it down clearly. Both the Karen and the Lucy hold exactly 30cl, and both are compatible with the same range of lids. The difference is in the profile of the glass.

The Karen has a straight-sided tumbler profile with clean geometric lines. It looks structured, modern, and precise. If your brand leans towards minimalism, contemporary design, or a bold graphic identity, the Karen is likely your glass. Its flat sides also lend themselves well to label application, giving you a smooth, even surface to work with.

The Lucy, by contrast, has a slightly curved and tapered profile that gives it a softer, more organic feel. It suits brands with a more traditional, artisan, or luxury positioning — think botanical gardens, heritage fragrances, and countryside retreats. The gentle curve catches the light beautifully, particularly in clear and amber variants.

Ultimately, the choice between Karen and Lucy comes down to brand personality. There is no difference in performance or quality — both are made to the same exacting standards. Many candle makers stock both and use them for different product lines within the same brand. If you are making candles for the first time and want to understand how scented candles work, either glass is an excellent starting point.

Colour and Finish Options

One of the reasons the Karen and Lucy range remains so popular is the breadth of colour and finish options available. You are not limited to a single look — you can build an entire product line using the same glass shape in different finishes:

1. Clear (Standard) — The classic choice. Fully transparent soda-lime glass that showcases your wax colour beautifully. Ideal for brands that use dyed wax or want a clean, honest aesthetic where the product speaks for itself.

2. Amber — A warm, honey-toned glass that instantly evokes a natural, artisan feel. Amber glass is popular with brands positioning around natural ingredients, essential oils, and botanical themes. It also offers a degree of UV protection for the wax.

3. Matt Black (Externally Sprayed) — A premium, luxury finish that has become extremely popular in the UK market. The external spray coating gives the glass a velvety, tactile quality that looks stunning on shelf. Browse our full range of sprayed candle jars for more options.

4. Matt White and Gloss White — Clean, contemporary options that work beautifully for spa, wellness, and modern homeware brands. White glass pairs exceptionally well with metallic lids for a high-end look. Explore our decorated candle jars collection for additional finish options including screen printing and custom decoration.

Wax Compatibility

The Karen and Lucy 30cl glasses are designed to work with every common candle wax on the market. Here is a quick guide to how the most popular wax types perform in these vessels:

Soy Wax — With its lower melt point (typically 46–52°C), soy wax is gentle on glass and produces excellent adhesion to the walls of the Karen and Lucy. The 30cl size provides an ideal diameter for a full melt pool with a correctly sized wick, minimising tunnelling.

Paraffin Wax — Paraffin has a higher melt point and delivers a strong hot throw, making it a favourite for heavily fragranced candles. The soda-lime glass in the Karen and Lucy handles the additional heat comfortably, and the wall thickness ensures even heat distribution.

Coconut Wax and Blends — Increasingly popular in the UK market, coconut wax and coconut-soy blends pour beautifully into the 30cl glass and produce an exceptionally smooth top. These blends are known for excellent fragrance retention and a clean burn.

Rapeseed Wax — A growing favourite among UK candle makers who want a domestically sourced, sustainable wax option. Rapeseed wax performs excellently in the 30cl size with good adhesion and a creamy, opaque finish.

Whichever wax you choose, we recommend leaving 10–15mm of headspace below the rim of the glass. This ensures a clean appearance, prevents overflow when the melt pool forms, and allows the lid to sit properly.

Lid Options

A good lid does more than just look attractive — it preserves your candle's fragrance between burns by maintaining the cold throw, protects the wax surface from dust and debris, and adds a premium finishing touch that elevates the entire product. All of the lids below fit both the Karen and Lucy 30cl glasses thanks to the shared GL thread diameter.

Browse our full candle lids collection for availability and pricing.

Silver Polished

Gold Polished

Copper Polished

Wooden with Rubber Ring

The silver, gold, and copper polished lids are ideal for brands that want a luxurious metallic accent. They catch the light beautifully and pair particularly well with clear and matt black glasses. The wooden lid with rubber ring offers a natural, tactile alternative that has become hugely popular with eco-conscious and artisan brands. The rubber ring provides an airtight seal, making it the best option for preserving fragrance potency between burns.

Why Professionals Choose Karen and Lucy

When you are running a candle business, consistency is everything. Your customers expect every candle they buy to look and perform identically, and that starts with the glass. The Karen and Lucy range delivers consistent quality batch to batch — the dimensions, weight, clarity, and finish are reliably uniform whether you are ordering your first case or your fiftieth.

Beyond quality, professionals choose Colorlites for competitive wholesale pricing with meaningful price breaks at higher volumes, fast UK delivery from our warehouse, and a proven track record with candle brands across the country. The glasses are also fully compatible with our decoration services, including screen printing and spray coating, so you can create a fully custom product without sourcing from multiple suppliers.

For makers working at different scales, we also offer the same quality and design philosophy in other sizes: the compact 9cl Meredith for travel candles and samples, the 20cl Karen for a mid-size option, and the generous 50cl Tub for statement pieces and longer burn times.

Ordering and Wholesale

The Karen and Lucy 30cl candle glasses are available to order individually or in bulk through our website. We offer price breaks on larger quantities, making it easy to scale your production as your business grows. Browse our full candle glass collection to see every size, shape, and finish we offer.

If you are looking for something bespoke — whether that is a custom spray colour, screen-printed branding, or a completely unique finish — get in touch with our team to discuss our customisation services. We work with brands of all sizes, from start-ups to established names, and we are always happy to help you find the right glass for your next project.

Ready to order? Visit the 30cl Karen or browse the full candle glass collection to get started.