How do you have a bone influence verts under 100%

…Without using envelopes? Everytime I weight paint verts so that they are not 100% influenced, they are influenced 100% when I rotate the bone! What am I doing wrong? Can someone help?

If the vertices are only influenced by one bone, they will always be influenced by 100% no matter what weight you give them. To change this behaviour you will need to weight their inverse value to another bone (ie. if one bone controls 75%, another must control 25%)

If your rig for whatever reason only requires the one bone, you will still need to create another to counter-influence the weights. All this bone would do is make the vertices try to stay in their resting position using whatever weight value you give it.