Rather than an ordinary block for a door stop I decided to bring nature indoors. This oak leaf shaped design is at such an angle that it should be able to slide under most doors keeping them open. When not in use it can be hung up on the door handle, with an acorn accessory to go along with it.
p.s. The leaf is actually printed upside down. By printing the leaf at a low resolution the angle causes a stepped surface. The leaf can then be flipped over and the stepped surface provides texture/grip for the floor.
I have provided the base files in .stl along with files already sliced in makerware to .x3g with the following resolution: Leaf - 0.3. Acorn_top, acorn_bottom and acorn_peg - 0.2. If you want to use a different slicing software using the .stl files you may need to adjust the scale of the base files. I altered them accordingly: Leaf - 65%. Acorn_peg - 96%. Acorn_top and acorn_bottom - 100%. Printing using the following settings on my printer resulted in the following usage: Leaf - 1h13m - 28.42g. Acorn_bottom - 12m - 1.76g. Acorn_top - 13m - 2.53g. Acorn_peg - 5m - 0.4g. I printed mine in Faberdashery's fantastic PLA - Greenery Green, Woodland Brown and Bling Bling Gold.
You could just use glue to stick together the acorn_top and acorn_bottom. However, I have provided an acorn_peg which can be used as a dowel to slot the top and bottom together without glue. If the acorn_peg is too tight or too loose you can adjust the scale to get a perfect fit.
The only other thing you will need is some string or ribbon to tie the leaf and acorn together. I used natural jute string for a rustic feel.