Interesting design effects can be created by blending two vectors together. Blending is used to generate shapes that smoothly change from one to another, as well as creating 3D visual effects. 

1. Draw two vector lines in the same direction on a vector layer and make sure they are both active by ⇧ (shift key) clicking on both of them with the Select Vector Tool.
   
   
   
2. Go to Vector Menu > Blend. A window opens showing two blending options:
   
   
   • Intermediate – vector lines are created between and parallel to the original vectors. The newly created intermediate vector lines follow the shape characteristics of the original ones in relation to how close they are to each original vector line.
   • Ruled – vector lines are drawn from one vector to the other, traversing between the two. The process of blending is analogous to moving a ruler along the original shapes and placing curves at regular intervals (set by the number of blending curves chosen).
     
     
3. Select the type of blend required and enter the number of curves you would like between the original shapes. The new vector lines will be added to the layer.
   
   In the snapshot below, we have chosen to blend using the intermediate method:
   

How to create a 3D box using vectors

1. Create two simple rectangles on a vector layer using the Outlined Rectangle Tool. Ensure they are proportional to each other, but make one slightly smaller than the other to give the illusion of perspective.
   
   
2. Activate both vector shapes using the Select Vector Tool and go to Vector Menu > Blend.
3. Select Ruled and set the number of curves to four, then click OK.
   
   
4. Re-activate the original shapes with the Select Vector Tool.
5. Go to Vector Menu > Blend and this time select Intermediate. Enter your desired number of vectors to blend by and press OK.
   

A similar method can be used to create parallel and gridded ellipses. Repeat the steps above but this time create a small ellipse inside a larger ellipse. The results obtained using the Intermediate option and the Ruled option are quite different. They can be particularly effective when used together.