The iron-on toner transfer thing has been around since laser printers came out. It doesn't work very well. Note the mention of needing a few tries to get it right. "Touch up" with a conductive ink pen and X-acto knife is often required. The resolution of this process is not that good. There also tend to be registration problems, because laser printer roller feeds are not precision devices. If you're doing modern surface mount components, it may not be good enough. There also tend to be registration problems, because laser printer roller feeds are not precision devices. You don't get plated through holes. So through-board connections have to be made by soldering in little wires. There are special rivets and tools available for this.

Other than as a curiosity, or for very, very simple boards for large components, this is more trouble than it's worth. Quick-turn one-off boards are so cheap now.