1000-grit mystery: just a theory... perhaps it depends on the pore size of the wood. As you reach 400 grit, the sanded particles may be roughly the same size as the pores and sort of lodge in them. As you go above 400, the sanding action may dislodge the larger particles, but the smaller particles are no longer large enough to get lodged, so the pores open up again and accept stain more readily. I would be interested to see the same test in a wood with much larger pores (like oak or ash) as well as a wood with no pores (like pine).

It would be interesting to see the end grain under a microscope to see the difference and to see how the particles have filled in the voids.

Somebody spilled a little science into this woodworking channel.

Great video, Marc! This is definitely very helpful to save time where we can but also get the look we need. I always love a good experiment video.

You are a freakin genius !! I sanded higher than normal on the end grain of my coasters today to try this out... and it worked... the end grain sides are very close in "hue" to the edge grain sides now.

Thank you for running this test

Mark, this was another great video. I really appreciate the videos where you perform tests.

Really, really interesting results! 😮

Very helpful demonstration.

Quite interesting. Thank you for sharing your results.

Hey I think I have an idea about the mystery of 1000 grit !!

Awesome info! Gonna save me some sanding time!

Well, I first read the "Premiered...." as 81 months ago instead of 81 minutes. I thought "Didn't think Marc had as many tattoos 7 years ago." lol

Phenomenal video as usual!

Amazing video! Great job. Thanks

Excellent, excellent video. Love these scientific based comparisons. Enlightening and saves me a ton of time!

You do great comparison videos my friend and this is no exception.

Thanks for another great video! Good information to have!

This is great information on a problem I didn't know existed. I'll continue to sand my entire projects to 400 for feel. As far as the thousand grit goes it might require more testing, but my theory based on a hunch is that you might be starting to approach a grit with similar size to the fibers themselves and you are opening up some of the fibers.

Awesome advice and job !