***** update *****It came to my attention, thanks to Laura B, that the link I put in the post didn't work. It has been remedied and now working. Please try again. Thank you. Chloe P.
***** update *****
As promised in my last post, I am going to explain what a "period" is. A period, or design period, is the number of sections your thread travels, from top to bottom, and coming up to top.
The above is a design diagram of bi-coloured scales. The first path, in red, travels one section when going down and another one going up, so total number of sections traveled is two, thus the period of this design is two.
This one here is a diagram of quad-coloured scales. It looks busy but please concentrate on the red line. It travels two narrow sections when descending, and another two going upward, so the period of the design is four sections.
You now know what a period means. Very good. Then, you might wonder what the difference between "period" and "repeat". A good question, indeed.
A design repeat is a minimum unit of design as you know, while a period is simply the number of sections the thread travels as explained above. It sounds exactly the same thing, I know, but let have a look at the diagram below.
This is, too, a diagram of quad-coloured scales, only in two colours instead of four. Placing two colours alternatively like this results in a very unique finish typically called "arrow's shaft feather" or just "arrows". Although the design is given a separate name from scales, it is still a quad-coloured scales design. You can see each thread travels four sections, so it's a period of four while the design repeat is 2 sections.
Make sense? Can you see the first two sections (in pink) of a period is exactly the same as the latter two sections (in light blue)? These two sets of two sections are identical therefore the smallest design unit is two sections instead of four only because you chose to arrange thread colours this way instead of four different colours, or red, red, blue, and blue and the design repeat would be four sections which coincides the number of sections which consist of a period.
Then, this leads to something called "rounds". When you experimented on the number of sections, you noticed that your stitching path did not always come back to the starting point until it made another round of stitches or two. For example, design period of four, like quad-coloured scales, fits nicely on even numbered sectioned thimbles, like twelve sections, with only one round. On the other hand, it won't fit on, say, fourteen sectioned thimbles until it make two rounds of stitches. Please have a look at below diagram.
When the first path come back to the first section, your stitch is located at the bottom instead of on top side and you have to make another round to finish that row of stitches. Please note that there are only two stitching paths, red and green, even though the period of the design is four sections. A "row" is stitches you make from starting point until it comes back to where you started and "round" is number of rounds you have to make until you finish a row of stitches. This fourteen sectioned thimble with the design period of four sections requires two rounds of stitches to complete a row.
I can give you another example where period and repeat do not match. Here is a thimble I used to explain how to simplify the diagram last summer. It is 28 sections in total with period of eight sections. The design looks far more complex than four coloured scales above, but the idea is the same: the second half is just a second round and a design repeat is four sections while a period is eight.
You really do not need to know all of this, but understanding the make of the design will help you to deviate to more complex designs. Next "how I do" will be about cheating a little to simplify the markings. Keep you posted.