I'm using Swiss Spruce for both guitars partly because I think the look is right but mostly because I think it's a wonderful pairing with Koa and this model guitar whether it is nylon or steel stringed. This wood is very light, stiff, and responsive to a light touch but certainly holds up very well to a little harder playing.
I went through all of my sets to find a closely matched pair. Both sets came in very light at about 5.7 grams per cubic inch. I also compared how stiff they were, both with and against the grain. Finally, I did the more subjective tap testing for tone and sustain.
The reason I'm going through all this trouble is to make as many things as close as I can on both guitars. There will be many more differences than nylon vs. steel strings when finished, but where I can, I'm going to start them off as close to the same as possible. In the end, I want to show what this guitar sounds like as a steel string and as a nylon crossover.
Here's a close up of the top wood, I'd tried to catch the silking in this photo even though this is dry and roughly sanded:
Gluing up the first top:
Thanks for viewing!