Re tags. As mentioned, I had ordered some 30 gauge soft aluminum sheeting from a place called whimsie (artsy-craftsy). I got a piece 12 inches by 36 inches for, including fast delivery, for $22. (Ordered Monday morning, arrived Thurs from across the country). Depending on the size I cut my labels, I should be able to get at least 150 or more.
They had a section on their site that this was the stuff they use for plant labels, so I took a chance. It's about twice as thick as soda pop cans, but you can still cut it with scissors. I use an old paper cutter for greater accuracy, straighter edges, and speed. It does curl a little, but is easily straightened.
I've tried soda pop cans but don't like them for several reasons - they are too thin, you can tear them and rip the wire right out of them. They don't lie flat, and the label on the back will always be visible. And they are sharp.
I've also tried the bottoms of disposable cookie sheets/pie pans, which works OK - much easier to work with than soda cans. But if you buy them new they are expensive, and are also too thin IMO. They are about the same 36 gauge as cans. They do lie flat however.
The 30 gauge heavier stuff is also sharp when cut, and if you have kids or grandkids or pets that chew, or if you tend not to be careful working with things, don't get it. That said, I like the stuff. It's heavier weight, can easily be flattened either with a rolling pin or between pieces of light cardboard, is relatively easy to emboss with a ball point pen. I think these labels will last for years and years which is what I want.
For the wire hole, I fold back the label about a half inch, then use an awl to go through a double layer for greater durability. I'm not sure that is needed however, but I like how it looks. This is also sharp on the back.
I've used mini blinds for years and love them, but they don't emboss... I know writing on them with pencil can last for years, but I want 'forever'. And I like to tinker. :)
If I was a sane person, I would've gone with metal labels from ebay. But I'm not. :)