As we learned in the article about tartans, a plaid is just stripe made in two directions. We use this aspect of plaids to stitch them as well.
As long as you know the colors, the stripes’ widths, and the sequence, you can stitch any plaid. They are all stitched exactly the same way.
We’ll use the Rob Roy plaid as the example. Begin by stitching the vertical stripes. The picture above shows the chart for this.
Since you stitched every other stitch, the result looks like very odd stripes.
Once the vertical stripes are complete, fill in the horizontal stripes. As you do what had been stripes, becomes a plaid.
You did it all with a blank canvas, some thread, and either a chart of the plaid or notes about the sequence.
The process is the same in any form of counted work, with any square stitch, and for a plaid of any type. Once you know the numbers, a plaid is one of the easiest patterns to reproduce.
There’s no need to make it complicated.