Optionalcolordefault gray [150,150,150]
Optionalfontfont family — default the report's registered default family (never inherits ambient font state)
Optionalfontpt — default 60; ignored when layout is 'stretch' (auto-sized)
Optionallayouthow to lay the text out — default 'single'
Optionalopacityopacity 0-1 — default 0.15
Optionalrotaterotation in degrees, counter-clockwise — default 0 (e.g. 45 for a diagonal stamp)
Optionalshowdraw on the first page too? — default false
Declarative preset — just give it a string and get a stamp centered on every page, with no need to write a render callback or know jsPDF at all (same pattern as createAnchoredBand, which did this for PageBand); reach for the full Watermark interface if you need more control.