what about the surrounding area?does it respond to sanding nicely?does the glue leave a stain? thank you for sharing, cheers
That's going to depend a lot on the blank itself and the nature of the flaw. Dense or stabilized woods won't see much staining, nor will "uniform" flaws. For example, natural voids, like bark inclusions or small knots where the knot itself is gone leaving just the hole, tend to fill nicely. Imperfections caused by tearout are more susceptible to staining/bleeding. And for softer woods, you can arrest the bleeding a little by filling the hole and quickly hitting it with some activator, although it's a good idea to fill a hole in stages in such cases so you don't have pockets of uncured glue that can then splatter when you turn past the cured glue.
The other thing that really affect the final look is the quantity of imperfections. Sometimes I'd rather have several voids to fill than just one, and a few times, I've even deliberately put holes in the blank to balance the look. That said, filled voids often look 100% natural when the surrounding colors are right.
I've also gotten better at spotting flaws earlier in the process, prior to final turning/sanding. This means I can fill a hole without worrying about surface staining. Even though it will cost you a bit more in glue, it's much better to fill a hole with 1/16" or even 1/8" of material left to remove, even if that means you may turn away the entirety of the flaw. It's one less thing for a tool to be able to catch on and either make the fix harder or even tear the blank apart.