Choosing the right glass tip size is mostly about finding the format that feels natural to you.
At 78 Glass, our handmade borosilicate glass filters are usually made in diameters from 6 mm to 14 mm, with a standard length of 30 mm ±1 mm. The diameter shown on the product page is the external diameter of the glass piece.
There is no single “correct” size. A smaller tip gives you a more compact format. A larger tip creates a more substantial setup with a different feel, visual balance, and airflow structure.
The best size depends on how you like to use it, what kind of format you prefer, and whether you want something subtle, balanced, or larger.
The Most Popular Size Range: 9–10 mm
For most people, 9 mm and 10 mm are the easiest starting point.
They sit in the middle of the range: not too small, not too large, and easy to adapt to different situations. If you are choosing your first handmade glass filter and do not have a strong preference yet, this is usually the safest area to start.
That said, size preference is personal. Some people prefer very compact pieces. Others want a larger format with more presence. The number in millimetres is only the beginning — the real question is how the piece feels in use.
Small, Medium, and Large Sizes
Here is the simplest way to think about the range.
6–7 mm: Small
Small glass filters are best for compact formats. They are light, discreet, and easy to carry. Many people like them for everyday use because they keep the overall piece smaller and more minimal.
A 6 mm or 7 mm glass filter is a good choice if you prefer something narrow, simple, and not too visually dominant.
8–10 mm: Medium
Medium sizes are the most flexible.
An 8 mm glass filter still feels compact, but gives a little more structure than a 6 mm or 7 mm piece. A 9 mm or 10 mm filter is the most universal choice for many customers, especially if you want one size that can work across different situations.
If you are unsure, this is the range to look at first.
11–14 mm: Large
Large glass filters create a bigger format.
They have more visual weight, more presence, and a stronger structural role in the final piece. These sizes are usually chosen by people who already know they prefer a larger setup, or by customers looking for something special, bold, or less minimal.
An 11 mm or 12 mm piece is a good step up from the medium range. A 13 mm or 14 mm piece is already clearly large and should be chosen intentionally.
The Best First Choice: One Size or a Starter Pack?
If you already know what you like, choosing one size is easy.
If you are not sure yet, a mixed starter pack is usually more practical.
Instead of buying one piece and hoping it is perfect, you can start with two or three different diameters and quickly understand your own range.
For example:
- 8 mm + 10 mm for a simple two-size start
- 7 mm + 9 mm + 11 mm for a compact-to-large range
- 8 mm + 10 mm + 12 mm for a balanced starter set
A three-piece starter pack also makes sense because handmade glass is not only about size. Color, shape, and small variations all change the character of each piece. Having a few options gives you more flexibility from the beginning.
Straight vs Tapered Glass Filters
Most 78 Glass pieces are straight.
A straight glass filter has a nearly even diameter from one end to the other. This creates a cleaner cylindrical format and is the most popular choice for most customers.
A tapered glass filter has a slightly conical shape, meaning one end is wider than the other. This changes the structure of the final format and can slightly change the feel and airflow.
Some customers specifically prefer tapered pieces, while others only want straight ones.
For us, tapered pieces are usually a smaller part of each drop rather than the main focus. They appear in limited numbers, and for some people they are exactly what they are looking for.
In simple terms:
- Choose straight if you want the most classic and predictable shape.
- Choose tapered if you like a more conical format and want something a little more specific.
Handmade Size Tolerances
Each piece is shaped, finished, and checked by hand.
Because of that, small variations are normal. Our standard length is 30 mm ±1 mm. Diameter is listed by external diameter, and handmade pieces may have slight natural differences from one piece to another.
This is part of the character of handmade borosilicate glass.
The goal is not industrial sameness. The goal is a clean, functional, well-finished object with its own individual presence.
Size Preferences Can Vary by Region
After working with customers at markets and events, we have noticed that size preferences can vary a lot.
In France and Spain, smaller sizes like 6–7 mm are often popular. In the UK, larger sizes such as 11 mm and above are more common. Germany is more mixed, with many customers choosing anything from 8 mm to 12 mm.
These are not rules, just observations. The best size is still the one that fits your own preference.
Quick Size Guide
Choose 6–7 mm if you want something compact, light, and minimal.
Choose 8–10 mm if you want the most versatile range. This is the best starting point for most people.
Choose 11–14 mm if you want a larger, bolder format with more presence.
Choose a mixed starter pack if you are not sure yet. It is the easiest way to discover what size works best for you.
Final Recommendation
For a first handmade glass filter, 9 mm or 10 mm is usually the safest single choice.
For a better first experience, choose two or three sizes instead. An 8 mm and 10 mm pair gives you a simple, practical range. A three-piece starter pack gives you even more flexibility and helps you understand your own size preference faster.
Glass tips are small objects, but the size changes a lot: the feel, the balance, the look, and the way the final piece is built.
Start with the middle range, try a few diameters, and let your preference become clear through use.