I want to reuse those bottles at home, but I don't want the label on it. I am planning to paint them with nature design. So how can I remove those labels in the fastest way possible?
To remove sticker with glue from a glass bottle, it is better you use less sharpened knife along with water.First, try to tear apart the sticker using your hands.Then soak the left overs on glass with enough water so that it could be easily peeled off from the bottles surface using knife. If you are dealing with a sharper knife, be careful.But less sharper one will do the trick.
Most paper labels on glass bottles (at least on commercial products) are glued with a water soluble glue. I've found soaking for a few minutes in the hottest tap water available lets me peel them cleanly, or scrape them with the back of a table knife. A quick scrub with a plastic wool pad will then remove the glue residue, then a rinse in hot water lets the bottle dry clean and clear. I've cleaned fifty-plus beer bottles (for brewing) with this method in well under an hour.
If the label is put on with a sticky/gummy adhesive, it is probably what they call a "cold flow" adhesive. I have found that warming the adhesive (fill the bottle with warm water) and peeling it off SLOWLY by pulling the label straight away from the glass works fairly well.
Watch the line where the adhesive is separating from the glass. If you see a bit of adhesive remaining on the glass, or the label delaminating, STOP and use a knife or razor blade to get the edge repaired. Then continue pulling the label away from the glass. If you get all but a few spots of adhesive or adhesive and paper removed, use a mild solvent like lighter fluid or alcohol to remove the last bits. The solvent makes the adhesive even gummier, so reserve this for those last few dots. If you put solvent on the entire label, you will have to use a lot of solvent and a lot of time getting it all off.
Another trick that seems to help with large cold flow adhesive labels is vinegar. The acid in the vinegar seems to break down the cold flow adhesive and make it easier to clean off. I've used this to remove the new car window stickers in one piece (they have valuable information you may want later). Be careful not to spill vinegar in your new car; the smell takes a long time to go away. I dampen a pad of paper towels with vinegar and press it against the label.
For conventional adhesives, water works best. If the label has a foil layer that keeps the water away from the adhesive, try scoring or scratching the label in a few places to let the water through.