Intrigued about a discussion on the forum about whether soldermask is needed between fine pitch pads, Brian decided to test it.
In the video of the test he placed solder paste on both the FR4 board material, and the soldermask, as well as some on a tined pad. Once done reflowing his results were in. Both the FR4 and the soldermask acted the same, no solder got stuck to either of them, while the tined pad got soldered as expected. The first video shows and explains the setup, while the one below has the results.
Via the forum