Oh no, finding a biro mark on a leather sofa is always a frustrating moment! Don't worry, it's a common problem and there are definitely a few things you can try to fix it. The search information provided wasn't very helpful, so here are some well-known methods based on general expertise.
The most important first step, no matter which method you choose, is to test it on a small, hidden area of the sofa. This will ensure the solution doesn't discolor or damage your leather's finish. A spot on the back or under a cushion is perfect for this.
A very effective and common solution is to use isopropyl (rubbing) alcohol. Get a cotton swab or a cotton ball and dip it in the alcohol. Gently dab at the ink stain, being careful not to scrub, as that can spread the ink. You should see the ink begin to lift onto the cotton. Keep using fresh swabs as you go to avoid reapplying the stain.
If you want to start with something gentler, you can try a bit of mild soap and water. Mix a small amount of clear dish soap with warm water, dip a soft cloth in, and wring it out thoroughly so it is only damp. Blot the stain gently. This is less likely to work on set-in stains but is a safe first attempt.
After you've successfully removed the ink, wipe the area with a clean cloth dampened with just water to remove any cleaning residue, then pat it dry. It's always a good idea to follow up by applying a quality leather conditioner to the area to restore moisture and keep your sofa looking its best.
