I just used Langka on three 3in scratches. Two were 1/16 inch wide. I applied the touch up paint last weekend and removed the "blob" this weekend. I was told by Larry Johnson (Langka president) that blobs can be removed several weeks later. So, I tried removing blobs that I touched up last August and it took them off just fine. The product is very easy to use. I highly recommend it. If you don't like the results, you can try again until you're satisfied.
The only real problem is that the Oxford Green touchup paint sold by BWM doesn't match. It comes out as a lighter green when finished. Somewhat noticable. Any suggestions on where I can find a better match???