Investing in good pencils, good paper, and good erasers helps avoid this… but it costs money. Likewise, drawing light lines before drawing heavy helps as well (but is a skill that needs honing.) When all else fails, as tudza says, just scan it and edit in GIMP/Photoshop.
Light box? Scan and edit it GIMP?
Every artist knows this pain.
Investing in good pencils, good paper, and good erasers helps avoid this… but it costs money. Likewise, drawing light lines before drawing heavy helps as well (but is a skill that needs honing.) When all else fails, as tudza says, just scan it and edit in GIMP/Photoshop.
Perfection’s worst enemy is the pursuit of perfection.