You can cut out a two-sided piece of wallpaper, like a 'V', lift it, then install your hanger.

If you move the artwork, just re-secure the wallpaper piece back down.

I've also successfully used straight pins for lighter weight items.

Dee

I've done the "V" dee suggested. It's easy and easily repaired later on.

You could also use picture rail molding, chain/cord & hooks so you never have to make another hole to hang your art.

Here is a link that might be useful: Picture Rail Hardware

Being a complete wallpaper newbie....if you slice the wallpaper it will peel up? I would think it would be glued down tight, no?

I had a lot of pictures in my old DR w/wallpaper. The only thing that required thick screws was a mirror. We knew it would stay there until we re-did the room.

The rest of the pictures were hung using either straight pins or the thinnest nails possible. Hardly visible when we took it all down.

I'm amazed at all the things I can hang with a straight pin! I keep them in my toolbox. lol

You can also put the nail in an unobtrusive part of the pattern. (and save extra wallpaper for small repairs)

I think with wallpaper though one tends to hang less on it. It also may make you more decisive about where things go and stay.

There are these great picture hooks called OOKS. I got mine at HD but lots of places sell them. While very strong, the nails are so tiny that when removed you have to look very hard to see the hole. I'd give them a try (maybe on the wall behind a piece of furniture or behind the TV on the wall and see what you think after you pull it out.