A leadlight can be beautifully cut and perfectly soldered yet still look wrong if the came is too heavy, too fine or poorly matched to the glass. Knowing how to select …Knowing how to select lead came starts with reading… starts with reading the pattern as a finished panel, not simply choosing a width that happens to be on hand. The profile affects your linework, the way light moves through the piece, how easily it assembles and, importantly, its long-term strength.
For traditional stained glass work, came is both structure and drawing. Its face creates the dark lines that hold the design together visually, while the heart and channels provide the framework that holds each piece of glass. A good choice supports the design without overwhelming it.
Start with the pattern and the finished scale
Before choosing a profile, look at the full-size cartoon. Ask where the eye should travel and which lines need visual weight. A small floral suncatcher may need fine, delicate lines; a large sidelight, fanlight or door panel generally needs more presence and more structural consideration.
The width visible from the face of the finished panel is usually the first thing makers notice. Narrow-faced came suits detailed work, small pieces and patterns where the glass itself carries plenty of movement. Wider-faced came creates a stronger graphic line and can bring order to busy, heavily textured or multicoloured glass.
There is no single “correct” width for a particular project. A broad face can make a simple geometric design feel intentional and architectural, but it may crowd a small-scale botanical design. Conversely, very fine came can look elegant on the bench but disappear when placed in a large window or leave a bigger panel looking underbuilt.
Understand the parts of lead came
Lead came is commonly described by its profile: H section for internal joins, and U or C section for borders and finishing edges. Within those profiles, the measurements that matter most are face width, heart thickness and channel width.
Face width
The face is the portion you see on the front and back of the finished leadlight. It determines the apparent thickness of every lead line. When comparing came, do not rely on a product name alone. Profile naming varies between suppliers, so it is best to check the actual face measurement and compare it with your cartoon.
A useful bench habit is to place short offcuts of several profiles directly over the full-size pattern. Step back from it. This quickly shows whether a particular line feels too dominant, too slight or just right. It is far easier to change your mind at this stage than after cutting glass.
Heart thickness
The heart is the central web between the two channels. It contributes significantly to the strength and stiffness of the came. A thicker heart is generally more suitable for larger panels, longer uninterrupted runs and areas subject to handling or movement. It can also be less forgiving to bend tightly.
A thin-hearted came is often easier to shape around curves and is useful for fine detail, but it should not be expected to carry the same loads as a heavier section. Do not use face width as your only guide: two cames can look similar from the front while having very different hearts and structural behaviour.
Channel width
The channel must accept your glass without forcing it. Most stained glass is nominally around 3 mm, but actual thickness varies considerably between glass types, manufacturers and even sheets. Rolled, heavily textured, handmade and some opalescent glasses can be noticeably thicker than smooth cathedral glass.
Choose a channel that holds the glass snugly while allowing normal cutting tolerances and assembly. If the channel is too tight, you may bruise edges, struggle to fit pieces and introduce stress into the panel. If it is too loose, the assembly can wander and require excessive cement to feel secure. Always test your intended glass in a short sample of came before committing to a full panel.
Match the profile to the glass you are using
Glass selection and came selection should happen together. A pattern made in thin, smooth cathedral glass may assemble comfortably in a standard channel, while the same pattern in a deeply textured or rippled glass may need a more generous channel. This is especially relevant where several glass types meet in one panel.
Do not assume that every piece has to sit at exactly the same depth. Minor variation is normal in leadlighting, particularly with handmade glass. What matters is that the glass fits without being forced and that the panel can be cemented and finished evenly.
If you are using a mixture of thin and thick glass, plan the joins before cutting. Sometimes a broader channel throughout is the cleanest option. In other cases, a local adjustment to the glass edge or a carefully chosen alternate profile may be appropriate. Avoid making the entire panel unnecessarily coarse just to accommodate one unusually thick piece if there is a better solution in the pattern.
Select came for curves, corners and borders
Tight curves ask more of the came than straight lines do. Fine, softer profiles bend more readily, but they can distort if pushed too hard. Wider or thicker-hearted came may need more gradual curves, careful stretching and considered cutting at intersections.
For internal lines, H came is the usual choice because it receives glass on both sides. For an outside edge, U came gives a neat finished border and protects the glass edge. Border came should be chosen as part of the panel design, not added as an afterthought. A border with too little strength can leave a large panel feeling flimsy; one that is too wide can make a delicate design look boxed in.
Corners also deserve attention. Mitred border corners can look crisp on formal geometric work, while butt joints are practical in many applications. Whichever method you use, ensure the border profile has enough substance for the panel and the intended installation.
Think beyond the bench: panel size and support
Lead came alone is not a complete answer to structural support. Panel size, aspect ratio, glass weight, installation method, exposure to wind or door movement, and the direction of lead lines all matter. A long narrow panel may need support even when it does not appear especially large.
Reinforcement options such as steel-reinforced lead, zinc or brass channels, copper restrip, or properly planned support bars may be needed depending on the design and installation. These decisions should be made early, because they influence where your major lines sit and how the panel will be finished.
A common mistake is choosing heavier lead in the hope that it will remove the need for reinforcement. Heavier came can improve stiffness, but it does not replace sound design or suitable support in a large or exposed panel. If the work is architectural, installed in a door or intended for a demanding location, consider the full construction system rather than the came in isolation.
Use samples to avoid expensive surprises
Experienced makers still make test sections. Cut a few pieces of your chosen glass, assemble them with the proposed came and check the fit, face width and bendability. Include a typical intersection if the pattern has many of them, and test a curve if one is central to the design.
Pay attention to the practical feel of the material. Does the came sit squarely on the bench? Does it accept the glass cleanly? Are the channels consistent? Does the line look balanced against the glass once viewed from a normal distance? These small checks reveal far more than a measurement on paper.
Lead came also benefits from proper preparation. Stretching straight lengths helps remove minor kinks and gives a cleaner result, but it should be done with control. Overstretching can narrow the channels, alter the profile and make fitting more difficult. Keep offcuts labelled by profile so future repairs, additions and matching projects are easier to manage.
A practical way to make the final choice
For most projects, make the decision in this order: establish the visual line weight from the cartoon, confirm the channel fits the actual glass, then choose enough heart thickness and border strength for the finished panel. Only after those points are resolved should you fine-tune around curves, corners and any reinforcement requirements.
It is tempting to buy one general-purpose profile and use it for everything. Keeping a familiar came on hand is useful for practice, repairs and small work, but a carefully selected profile is one of the clearest signs of thoughtful leadlighting. If you are unsure between two sizes, prepare a small sample with each. The panel will usually tell you which one belongs there.
Ready to choose your profiles? Shop our Lead Came collection — H section, U section, round and flat profiles available.