Many designers will pay attention to the Stitches Per Inch (SPI) of the textile related products such as bags, clothing, footwear, etc. This is a very small thing, but it cannot be ignored!
Q: What is the Stitches Per Inch (SPI) ?
A: How many stitches are in each inch.
Q: Does SPI affect anything?
A: SPI will directly affect "seam strength" and "appearance", and so on.
Q: How to measure SPI?
A: Since it is calculated in terms of how many stitches per inch. We can use the measuring ruler to count number of stitches. The SPI is 7 in the photo of article.
Q: Will the bag get more stronger when the SPI is higher?
A: "Too much of a good thing!" Too many SPI represent the more needle holes on the fabric. Everyone knows that "a line is made up of countless dots." Excessive needle holes may damage the fabric and even make the fabric easier to break.
In summary, I hope everyone knows more about the "SPI" now.
Too many→ You are wasting the efforts.
Too less→ That is a cut corners work!
Both are not good!