Bold initial signatures
A short mark written with enough pressure and weight to feel deliberate rather than rushed.

A short mark can easily read as careless, and heavier pressure is the simplest fix. Two thick strokes look considered in a way two thin ones do not, even when the letters themselves are identical.
Which letters earn their place
Two letters is the usual answer, three when your name is common. Bold initial signatures work because the reader is not decoding anything: they are recognising a shape they have seen before, at the bottom of a page they already trust.
Bold initials need a pen that lays down an even line under pressure — a fine ballpoint tends to skip and thin exactly where you press hardest, which shows most on a short mark with few strokes to hide it.
Make the short mark hard to copy
Anything short is quick to imitate, so the defence is not length but habit: an unusual join between the letters, a fixed baseline, a stroke that always ends in the same place. Consistency is the part a copyist cannot see.
Keep the weight consistent between the two letters. If one initial is heavy and the other faint, the imbalance is more noticeable in a two-letter mark than it would be across a longer name.
Where initials work best
Initials belong where space is short and repetition is high — initialling each page of a contract, marking a drawing, signing off an internal approval. For a first signature on a legal document, most people still want the full mark.
You can build any of these in the browser: open the Signature maker, draw or type your name, and place the result straight onto a PDF or Word file. Nothing is uploaded — the document never leaves your device.