It probably isn't as simple as that. :)

I'm sure that it depends a lot on the kayak design, the characteristics of the timber used, the techniques and tools used, the skill and the patience of the builder.

The reason I used 1/4" strips for the first two was just that in spite of the fact that I had done what I thought was an enormous amount of research, I hadn't come across the suggestion of using thinner strips. As it happens, I managed to get the 1/4" strips to fit well enough that I wouldn't have sanded through them even if they had been 1/8" thick.

That may have had more to do with the other factors I mentioned rather than my skill. If I had known that a lot of reputable and respected builders used 3/16" strips, I probably would have started with them.

I guess my point is that it is probably possible to create problems for yourself with any thickness strips. I believe that there would be less chance of sanding through well fitted thin strips than very badly fitted thick ones.

Different things seem to work for different people.