Pattern Match Research
The Carpet & Rug Institute has information on Pattern Match at: http://www.carpet-rug.com/drill_down_2.cfm?page=6&sub=8
The IICRC REFERENCE GUIDE FOR INSPECTION OF TEXTILE FLOORCOVERINGS contains the following definitions in its Glossary of Terms:
pattern match - Lining up patterned carpet in such a way that the design element is continued across seams, making the finished installation appear uniform and cohesive. Patterns must be matched in the same way as they appear on the carpet itself, either in a set match or drop match.
pattern runoff - Visually apparent streaking in patterned carpet resulting from linear juxtaposition of pattern elements in one direction. This is not necessarily a carpet defect, but rather it is inherent in certain designs. Long runs of carpet with complicated geometric or busy patterns should be laid out and evaluated for pattern streaks prior to installation.
skew -Seam or patterns that deviate from a straight line.
According to the FLOOR COVERING DICTIONARY it says this about PATTERN RUNOFF.
PATTERN RUNOFF - An uneven installation off patterned carpet in a room with perpendicular walls in which the pattern disappears (appears) at a slight angle to the wall.
According to the FLOORCOVERING DICTIONARY it says this
about BOWED OR SKEWED PATTERN: