The given name is the usual choice and the safest one, because it is the letter the recipient answers to. A family name initial reads as slightly more formal and works well when the piece is meant to mark a family connection rather than an individual.

Some people wear a letter that belongs to someone else entirely, such as a child, a parent or a partner. Nothing about the design signals whose letter it is, which is exactly why the form suits that use.

If the choice is genuinely open, a single letter in a plain block or script face is the version least likely to sit unworn, because it commits to the least.

Not usually, and that is a design decision rather than a fault. Script depends on contrast between thick and thin strokes, and the thin passages are where the eye picks up the letter's identity. In metal those passages have to be kept substantial enough to cast and to wear.

The consequence is that script capitals tend to read as an elegant mark first and as a specific letter second. At larger heights the ambiguity disappears, because the thin strokes have room to stay genuinely thin.

Block letters give up the movement of script and keep the legibility in exchange. Neither approach is better than the other; they solve the same problem from opposite directions, and the choice depends on what the piece is meant to do.

Because letters are not built to a common width. In almost every alphabet the height is the fixed dimension and the width follows from the shape, so M, W and Q occupy far more area than I, J or L when both are made to the same stated height.

This matters when a design is being bought unseen. A listing quoting a twelve millimetre height describes a narrow object if the letter is an I and a broad one if it is a W.

A few designs are drawn to a fixed width instead, which keeps a set of pendants visually consistent but makes the narrow letters look stretched and the wide ones compressed.

There is no fixed threshold, because it depends on the letterform and on how far away the reader is. As a rough guide, a block capital of about eight millimetres is readable by someone across a table who is looking for it.

Script and gothic faces need more height than block to reach the same clarity, because more of their identity is carried in fine detail that has to be thickened when it is made in metal.

Below roughly seven millimetres most letters begin to function as a texture or a mark. That can be the intention, particularly on a piece meant to be noticed only at close range.

In the traditional three-letter arrangement the family name initial goes in the centre and is drawn larger than its neighbours. The given name initial sits to the left of it and the middle name initial to the right, so the reading order is not the order the name is spoken in.

Where all three letters are the same size, the convention reverses and they are set in ordinary order: given name, middle name, family name, left to right.

For two letters representing two people, there is no established rule. Most designs simply set them side by side at equal size, sometimes separated by an ampersand or a small linking motif.

Two separate letters, one worn by each person, is the more flexible arrangement, because each piece still works if it is later worn alone. It also avoids the problem of deciding which letter takes the left-hand position.

A single design carrying both letters reads as one object and makes the pairing explicit. Interlocking and overlapping treatments are common here, where the two letters share a stroke or sit in the same enclosing outline.

Where the two letters are very different in width, a paired design tends to look better with the wider letter set slightly lower or behind, so the composition does not lean.

Because the chain passes through a point that is not directly above the letter's centre of mass. Letters are asymmetric shapes, and the piece rotates until the heaviest part hangs lowest, which is often not the orientation the letter should be read in.

Designs with a single small ring at the top rotate most freely. Those with a wider fitting, or with two attachment points spaced along the top edge, are held square and cannot spin.

If a design already owned turns persistently, a jeweller can often fit a flat, wider fitting in place of a round ring, which resists rotation because it has a preferred plane.

They do. A descending tail puts metal below the main body of the letter and shifts the balance point downward and, in the case of Q, to one side. The result is a piece that hangs lower than its stated height suggests and may sit at a slight angle.

Designers usually compensate by thickening the tail where it meets the bowl, or by curling it back so it returns under the letter rather than projecting away from it.

A projecting tail is also the part most likely to be caught, so the tighter and more enclosed the tail is drawn, the less exposed it is in wear.

An outline letter carries its load along a narrow band of metal rather than across a filled area, so the thickness of that band matters more than it does on a solid design. A wide, generously drawn outline behaves much like a solid letter of the same size.

The vulnerable places are the points where the outline changes direction sharply, and any part of the band that stands away from the body of the letter unsupported.

Solid letters distribute a knock across more metal. That is the practical case for choosing solid where a piece is going to be worn constantly and not thought about.

It does, and the effect is not simply decorative. Stones set along a stroke break that stroke into a line of separate bright points, which the eye reads as a dotted line rather than a continuous edge. At small sizes this can soften the letter's shape.

Set against that, stones catch light from angles that flat polished gold does not, so a set letter stays visible in dim conditions where a plain one goes quiet.

Designs that set stones on only part of the letter, or that outline it in stones while keeping the strokes plain, tend to hold the shape better than those that pave the whole face.