I'm new to 3D printing, but my printer supports Linear Advance. I heard that it offers improvements in print quality. I used Marlin Linear Advance Pattern Generator to generate a print with horizontal lines at a variety of k-values.
Which K-Value would be best from my below image?
As a general answer to evaluate the effectiveness of the K-factor, when the K-factor Calibration Pattern generator output print is inconclusive (probably not in this case), printing a tower at various K-factor values might give you more insight, e.g. like:
To vary the K-factor with height, a similar procedure as in How does one use a heat tower? can be followed to insert a new K-factor with G-code M900.
Go with the sort of tower 0scar suggested and look for corner bulge/rounding. It's a lot more useful than the single-layer test pattern from the Marlin site, which I've found can be misleading.
With that said, just looking at your test print, I would go with the lowest K factor that gives acceptable-looking results, so around 0.5 or so. Overshooting is more likely to harm your print quality than undershooting, and will limit your print speed too. When I used the original bowden on my Ender 3, my calibrated K factor for PLA was 0.6, so I think this is in the range of what's expected.
