The present invention relates to an aqueous colloidal gold solution,
comprising (a) nano-particular gold particles, (b) a compound having a
polar tertiary amino group conjugated via a hydrophobic aromatic residue
with a weaker alkaline group, and (c) a stabilizer comprising a mercapto
group (--SH) and an acidic group, in particular a sulfonic acid group
(--SO.sub.3.sup.-). This gold solution uses an ecologically compatible
medium and is suited in an especial manner for writing and for printing,
also for inkjet printers, since it has a long-term storage life and
generates an attractive metal-like gold sheen.