
Experimental work results to deter theft.
First thing, thanks to everyone for their suggestions, in particular those who pointed out the use if the Barcode for used book dealers.
The book shown, has had multiple things attempted. There is clear packing tape over the ink stamp and the white labels.
My initial work will be to try to use easily available common household items and start testing the simplest ideas first and then work from there.
First let me report on what doesn't work.
Just ink stamping it on glossy covers is messy, smudges off and can be removed with a facial tissue and rubbing alcohol or just a lens wipe. It tends to smear from ordinary handling. Rubbing the surface with rubbing alcohol as a surface pretreatment doesn't improve the printing. See the mess the ink stamp has become.
I used a sharpie over barcodes and easily wiped off the sharpie with 91% alcohol as sold by Walmart.
I used a sharpie on the back cover to see if the ink solvent mixture would penetrate through the cover and spoil the barcode. Some slight graying of the white could be seen in one case, but not another. Further, in the case of the one book where some slight penetration, the barcode turned out to be on a lable that went on the printed book, but was beneath the glossy finish. THIS LINE OF INQUIRY WILL NOT BE FURTHER RESEARCHED.
So what works and what did I do.
- I did vertical lines with a ball point pen on the bar code. It breaks up the glossy coating. When I went over with a sharpie some of the marker penetrated into the paper and I think helped make the bar code unusable.
I then put an adhesive lable on it which would now bind to paper fibers exposed. I in stamped the paper label. I then applied packing tape over the labels. When trimming the label, you should make sure there are no sharp corners, by cutting it so corners are curved. See picture. I RECOMMEND THIS AS A MINIMAL THING TO DO NOW FOR BAR CODES AND ISBN NUMBERS..
I did another book and it had a barcode that was smaller and it looked better than the book in the picture. I strongly recommend AGAINST having the white labels overlap.
For cases where I stamped the book, I applied packing tape over it. It at least stops smearing and it can't be removed by rubbing alcohol.
I did Experiment #1 above with scratching with an exacto blade and it didn't seem to work to break up the coating. Of course coating chemistry and specifications might vary. So this result isn't conclusive.
Next work.
I ordered clear adhesive mailing labels to try out. They won't have corners that can be caught by finger nails easily to remove them. However, I don't know if they will stick as strongly as packing tape. They will be more convenient to use.
Instead of trying to scrap off the coating, I am going to try shallow cuts with the exacto so the sharpie can soak into the paper.
I am going to test other common house hold liquids if used as a pretreatment. they modify the surface for better ink stamping and resistance for removal.
I am going to look at sanding/abrading the bar code. Then sharpie. Then white label, then clear adhesive film.
Wood branding burners. (Maybe.)
Nail polish remover to remove the cover coating.
Embossing stamp. Though this might be more than what people want to spend.
I will issue another report on my results.