On the PC, how do you tag something to look for as far as Junk is concerned? I see the PRESS T to tag, but it's greyed out. I can go over to the items needed to make an item, but the T still can't be pressed. ??

I think it's only available when you actually lack some materials. Try to craft something that requires more than what you have, or go try to craft from a settlement where there's no such material.

There are two ways to tag components for searching. The first is from a crafting station - bring up a crafting recipe for which you lack some components, hit T, and each of the lacking components will be tagged. To use this option you need to lack the components.

The second method is to access your PipBoy inventory, go to the Junk tab, and press C for Component View. You can then highlight a component on the list and press Q to tag it. To use this option you need to have the components, or at least a junk item that contains them.

Oh thanks, that's much better with the junk tab. I've skimmed through it only once or twice, and didn't even notice the component view.

Thanks got them tagged.

Lucky for you. I'm on PS4 and that feature broke on the third day I was playing. It's been greyed out and nonfunctional ever since.