Please tell me what makes a GREAT tartan design.

[Lyle1]

Beauty is definitely in the eye of the beholder, and I don't think I could explain why I personally like a particular tartan. In general (even in things not related to tartans), it is not a specific color or hue that attracts me, but how it is used in a given situation. In tartans, I enjoy the variety of colors and hues, as well as the many combinations that are used. I prefer tartans that have a pattern that is easily discernible from a distance of twenty feet or so and that have an obvious repeat to the pattern. I am drawn to all of the tartans illustrated here, so far, except the Jacobite, and I think it is the shade or hue of the larger blocks of yellow that put me off. However, I would have to see it pleated to make a final decision.

I guess I know what tartan I like when I see it, but I might change my mind the next time I see it.

[OC Richard]

...I don't think I could explain why I personally like a particular tartan.

...it is not a specific color or hue that attracts me, but how it is used in a given situation.

I prefer tartans that have a pattern that is easily discernible from a distance of twenty feet or so and that have an obvious repeat to the pattern.

The first thing, explaining why we like something, is the hard part.
I took a lot of art classes and many instructors banned the word "like". Their point was that it was that it's very easy to say we like or don't like something, and doing so requires no thought. The hard part is to put aside like/don't like and to really discuss what makes a piece of art effective. This applies to tartans, as each tartan is a work of art, a painting or composition in a way.

It's extremely difficult to pinpoint what makes some tartans more striking to the eye than others. For my own eye, as I said above, much of it is about the structure. But on the other hand some tartans have such wonderful use of colour that the structure almost doesn't matter.

Now about the last statement above, about tartans having a pattern that's discernable at a distance, that's especially true for tartans used by a pipe band. Pipe bands oftentimes pick a tartan that looks good when worn by an individual and veiwed up close, but when worn en masse and viewed at distance, is too diffuse or has too weak a structure.