Most writing problems blamed on a pen are really paper problems. These are the checks we use.
1Weight is a hint, not a promise
Heavier paper (around 80 g/m² and up) usually resists bleed better, but coating matters more. Some thin papers handle ink beautifully.
2Look for sizing and coating
Sized or coated paper keeps ink on the surface, so lines stay crisp and colours show sheen and shading. Uncoated copy paper often feathers.
3Feathering, bleed and show-through are different
Feathering is fuzzy line edges. Bleed is ink reaching the back of the page. Show-through is only seeing the writing from the other side, which is usually fine.
4Test before you commit
Write a line with your wettest pen and broadest nib, wait a minute, then check both sides. Note the drying time too if you are left-handed.