I have been looking for a suitable piece of timber to use as a straight edge for a while now. A few weeks ago I found this piece of Ysterhout that has been kicking around the shop for the past three years. I did not even consider Ysterhout as an option as it is not particularly stable in my experience. When I picked up this piece while ferreting around for a suitable piece of Witpeer, I saw that it was dead straight with grain to match. It is the piece on the right in the picture below.
I planed it down to a thickness of a ½” over the coarse of several days and it stayed dead straight. The design I chose has the specific purpose of exposing as much end grain as possible in an attempt to help the timber to adjust to changes in ambient humidity in no time.
After shaping it as pictured, I left the straight edge for a few days before fine tuning the business end.
A coat of Tung oil finished the job.