I started making my own picture frames and tried some hard corner clamps but found they didn't always have enough pressure for a strong adhesive bond. I tried this little ribbon clip and it was just what I needed. I was so impressed that I bought a second one to be able to work with more than one frame at a time. One reviewer complained that it didn't give 100% accurate viewing angles. This is because there are no hard corners to work with as it is a flexible band/compression clamp. To solve this problem, I scale the project down about half, then use a hard triangle and adjust to get perfect angles, then scale down a bit more and check again. I've had great success with it. If you want or need a 100% hard right angle with no control you'll have to build a jig, but it's a bit of a chore and you might not get as much compression for the clamp. This band clamp works great if you understand its limitations and are willing to review and adjust.