First of all, I love that all the pages come numbered and that there are designated contents pages! This is a dream and I wish more notebooks did this. You can also see how gel pens take to the paper - no bleeding or feathering!
Next up: fountain pen. This was written with a Pilot Kakuno with a fine nib and was inked with a blue Pilot cartridge. I've shown both sides of the paper - both of which are written with fountain pen - and you can see there is no show through and again, no bleeding or feathering.
Finally, I do like to draw illustrations from time to time and this one was drawn with a Kuretake Zig Cocoiro brush pen and again, I've shown both sides of the paper. No bleeding, feathering and minimal show through!
Honestly, Leuchtturm 1917 notebooks are a no brainer if you like to use inky pens and they come in a wide variety of colours. Aside from it getting quite expensive if you go through them quickly, I can see no flaw with this brand of notebooks.
What's your experience with Leuchtturm 1917 notebooks? Have you found a brand similar to this in design, quality and price? :)