Question

Eight-end regular sateen fabric can be woven with move (step) numbers of:

• A. 2 or 8
• B. 1 or 7
• C. 3 or 5
• D. 4 or 6

Hint:

For an N-end sateen: choose a number coprime with N, but avoid 1 or N–1, to maintain proper sateen distribution.

Answer 1

The Correct Option is C

A regular sateen weave requires a systematic distribution of interlacing points so that the warp or weft floats appear evenly spaced without forming visible diagonal twill lines. This uniform distribution is obtained using a mathematically correct step number (also called the move number). The step number determines how far the next interlacing point shifts from the previous one. For an \(N\)-end sateen, the step number must satisfy two strict conditions: 1. It must be coprime with \(N\) (i.e., the greatest common divisor must be 1).
2. It must not be 1 or \(N-1\), because these produce a simple sequential shift that generates a twill line rather than a sateen effect.
For an 8-end sateen, the integers less than 8 are: 1, 2, 3, 4, 5, 6, 7. We now identify their relationship with 8: - gcd(1, 8) = 1
- gcd(3, 8) = 1
- gcd(5, 8) = 1
- gcd(7, 8) = 1
Thus, the valid coprime numbers are 1, 3, 5, and 7. But step numbers 1 and 7 must be rejected because they simply shift the pattern by one position (or by N–1), which creates a clear diagonal progression—essentially a twill. The remaining viable step numbers are 3 and 5, and these produce the classic 8-end sateen distribution by maximizing the spacing between interlacings while avoiding any diagonal pattern formation. Therefore, 3 and 5 are the only correct step numbers for an eight-end regular sateen weave.