Do you have crown molding? Put the hook in molding and hang the pics from ribbons or cords. It is a lot easier to fill in the hole and dab on a splotch of paint than it is to try to repair a hole in the wallpaper without it being noticable.

The short plain straight pins work great. If a picture is semi-heavy, use a very thin nail.

If you can, pick an area of pattern to put the smallest nail you can in.

Cover the ends of the wires and attachments of the wires to the back of the frame with cloth tape or felt. I have seen more noticeable damage to wallpaper from these things rubbing and scratching the paper, than a nail hole.

Think long and hard about what and where you want to hang, and leave it. A wallpapered room is not the place to juggle your artwork around (from someone who leaves things propped on the floor for years to avoid committing to a hole in the wall.)

Wow! What a great idea!

Gracie's idea is very good!

The 3M Command hooks, asked about by the OP, are not recommended for wallpaper, 3M says.

Only other thing I can think of is a picture rail, but you need to install that with nails, too.

Did you have wallpaper left over? I think that if you really love the paper and know you want to live with it for a while, it'd be good to get an extra roll for matching (like maybe if someone in the household gets hair dye on it, or spills medicine that stains, or maybe someone gets dizzy, goes to grab a towel bar and the towel bar pulls off the wall, etc..)

Having extra will ease your mind about putting a nail in the wall!

Genius! Thanks Gracie!

"Cut an upside down "V" shape in your paper with an exacto knife, pull that section down, (don't rip it off), then insert your screw, whatever. If you change your mind you can pull it back up and paste it into place."

GREAT tip, Gracie!

I like Ooks hangers. I can't get into ooks.com but they look like this. Pin diameter for average size frame only leaves a small hole in the wall. Used to be harder to find, only had them at LNT. Now Lowe's carries them as well as Ace. Don't have to worry if it's drywall and something heavy, they still work. I have a honkin' big mirror hanging on two of the triple hangers, in drywall. No problems, no giant holes in the wall.

My decorator hung all my pictures with the upside down "V" and it does work. We had to rearrange some furniture which meant moving artwork and you couldn't tell where they had hung.

All great ideas! Thanks so much to all of you. Now the hardest part is trying to figure out WHERE to put the pics!!!!