Lace is liable to stretch as it is passed through the feed mechanism, in which a vision system is engaged to detect the changes of the motif and find the cutting path (river) across the lace pattern. The vision system has to work with many different lace patterns, sizes and tolerate misalignment, stretch and other distortions. A Fuuy Reasoning Rule-based technique is employed in order to overcome the problems of flexibility. Several experiments have been canied out using lace patterns of varying complexity. All cutting paths across the patterns were successfully found. Experimental results indicate that this method can correctly detect the river path in different lace patterns.