When I saw the piles of negative reviews this product has, I was a little hesitant to try it.I guess a review depends on the expectation one has of the product. This bottle and jar cutter is being sold as an arts and crafts product, however, I saw its potential as being a green product and I brought it as such.Now, instead of recycling all of my glass, I’ve been turning many of them into drinking glasses.Although glass is 100% recyclable, it takes 2,700 degrees to smelt it and if a colored glass makes its way into the smelting oven it can ruin the whole batch. [I learned this from the Recycle Bank.]So, to set an example for my kids, I took a chance on this bottle and jar cutter and I’m glad I did.Here’s what I’ve learned…* For safety reasons, you must follow all the instructions to the letter. Also, I didn’t pay attention to the part of oiling the cutting wheel and I ruined one of them.* It takes time to get it just right. I few bottles will break, crack or split. You just have to make it over the learning curve.* The jars and bottles of food that we buy are mass produced for wholesale commercial purposes. So, even once you’ve learn how to use the cutter, imperfections can cause the glass to crack.* Using a wet stone (or sharpening stone) on the rough cut helps save time. I find used wet stones at my local flea market.* Some glasses don’t come out looking good. At my house we call those the pirate drink glasses. And if you have kids like I do, this too can be a lot fun. Imperfections in the glass add to the pirate effect. Try jars from different brands and foods to see the differences in them. Anyway, I’ve made a lot of glasses and given some away. People really enjoy knowing it was once a jar.* The best drinking glasses can be made from jars of Goya Sofrito and jars of olives. These seem to be the perfect size and shape for drinking out of. Plus they don’t take up much space in the dishwasher. Wine bottles make a better glass for enjoying smoothies. And gravy jars make small drinking glasses.* Buying a pretty jar or bottle with the intention of making a drinking glass out of it is fun, but don’t spend too much because you never know if it will break.Hope this information is helpful to you.