White Spots and Diagonal lines in Oriental Rugs
Jan M. from Edmonds called about her Chinese rug and the white spots she noticed after it came back from cleaning. “What happened?”
“White Spots”
Both the “white spots” and the “lines” originate from hand-tied knots in the foundation of the rug.
The rug’s pile is actually hand-knotted around a foundation of warp and weft yarns. Vertical yarns (the warp) will be strung under tension on a loom. The wool yarn that becomes the face pile of the rug is hand-tied around the warp. After each row of knots is tied, a horizontal yarn (the weft) is woven between each warp yarn. Essentially, the rug maker is weaving a flat fabric foundation at the same time the pile is being knotted in place.
In most hand-made Oriental rugs, cotton is used for the rug’s foundation because it has very good “dimensional stability” – meaning it doesn’t shrink or stretch as much as wool and is stronger than other natural fibers. However, warp yarns may break requiring repair by tying in a new piece of cotton. Every broken warp yarn will generate two repair knots, and these become the white spots that Jan inquired about. These “white knots” are considered to be a part of a normal hand-knotted rug’s production.
1:30 video showing warp repair knotting
Elizabeth H. from Issaquah said that her entry rug is starting to look like it was a victim of an industrial accident. “When vacuuming, I noticed some distortion in the nap that looked like a short diagonal line. Looking closer there seem to be several more. I never noticed them before – what causes this?”
Diagonal Lines / Sections Lines / Lazy Lines
Most larger rugs are woven by several weavers sitting side by side. They all work at the same rate and the weaving progresses across the full width of the rug, one row at a time. If one weaver works on a larger rug, they may build several rows in one area rather than shifting their position to complete a row across the entire width of a rug. The weaver will tie a knot on each row at the end of their reach, shift position and repeat the procedure. This will result in a diagonal line of knots between each section of weaving.
Whether this is considered a normal part of rug weaving is open to debate. Those that feel this style of weaving is appropriate call these “section lines”. Others that think the weaver should complete a full row call them “lazy lines”.
When a rug is new, these cotton knots may be hidden by the pile of the rug or may have been recolored with a marking pen by the rug weaver. When the rug is put into service the knots can work to the surface, the pile becomes worn and compressed and the colored marking can wear away. Usually the rug is becoming soiled at the same time, with the soil disguising the knots. Cleaning removes the soil and the knots become more apparent.
Unfortunately, the diagonal lines in Elizabeth’s rug and the spots in Jan’s rug will become more prominent with use.
What can be done about this?
The white cotton knots can be removed from the finished rug and repaired with reweaving. Reweaving the multiple knots can become tedious and costly. Many rug owners accept this as part of the hand-made appeal of their rug. Although not a permanent fix, some may decide to visit an art supply store and do a little recoloring of their own.