A method and system for creating guilloché base pattern with two-dimensional periodicity in a plurality of replicate patterns is shown wherein the creating can be assessed in real-time for pattern acceptability by a user. A base pattern is set on an imaging device in vector space relative to a set of predetermined pattern nodes. The base pattern is modulated via a user interface by adjusting positions of the pattern known for selectively controlling curve shapes of the pattern. A guilloché mark is illustrated by display on the imaging device of the adjusted base pattern and a compilation of associated replicate patterns for user assessment of the mark.