Wall putty is typically available in either white or blue, with some products also available in grays or other colors. Putty of various colors is regularly marked as safe for walls and is unlikely to pull off paint during removal. When working with white or light-colored walls, however, it's advisable to use white or neutral-colored putty, as more colorful products are more likely to leave a stain on the back of the poster or even the wall.
Even if you use putty that's designed to remove easily from walls, you cannot use it on any type of wall surface. Avoid applying any form of putty to wallpapered walls, whether flocked or smooth. Also avoid using putty on walls with peeling or fresh paint. Sand and repaint as necessary, following the manufacturer's instructions to ensure that the paint dries completely.
In addition to the limitations on wall surfaces, putty is only advisable for use with certain items, such as posters or other lightweight decorations. For larger posters, apply putty to all the corners of the poster and along a few sides. Hanging an excessively large or weighty item will typically cause the putty to peel cleanly off the wall, but the fall may damage your decoration. Potentially, an excessively weighty object could take some paint off the wall along with the putty.
If you need to fasten a heavy object to the wall or live in an area where earthquakes or other disturbances regularly occur, you can use an extra-strong putty. Marketed for use in earthquake-prone areas, this specialty putty is reusable and removable and does not remove paint from the walls. While normal putty is primarily designed for posters and small artwork, extra-strong putty can offer an additional measure of support for china, pictures and other objects hung on the wall by hooks or other devices.
Most putties are designed to come off of walls without removing any paint. If you are removing old putty of unknown origin from a wall, however, you run some risk of wall damage. If the putty leaves a sticky residue, you may gently remove it with a small amount of nail polish remover, rubbing alcohol or a paste made of baking soda and water. Before using any cleaners or other products on a visible area of wall, first test them on a hard-to-see patch, such as along a baseboard or behind a piece of furniture.