Agreed, Kester's solder is what MANY professionals use(myself included, pretty much every place I've worked uses it, & I've been with over a half dozen different employers in the electronics field), it's quality stuff, & can be bought at a MUCH better price than the stuff you see at Radio Shack or most R/C related companies(& that tiny bit of silver content in some of them isn't enough to make a big difference in the quality of connection, especially since the technique & tools you use are FAR more important to getting a good low resistance solder joint). Trust me, you will not be disappointed....