Making blends with steps and spines in Vectornation by Zaweba

Few tools save as much repetitive work as a blend. Give it two objects and it fills the space between them with in between shapes, changing size, shape and colour step by step. In Vectornation by Zaweba the blend is a live object, so the steps update when you move or recolour either end.

You can start one in two ways. Pick the Blend tool (W) and click the two objects in turn, or select both and use Object > Blend > Make (Ctrl+Alt+B). Either way you get the same result, and the choice is mostly about whether your hands are on the keyboard or the mouse.

Choosing the spacing

A blend needs to know how many in between objects to make, and there are three ways to tell it.

Smooth colour works out the number of steps for you so that the colour change looks continuous. This is the setting for soft transitions, such as a glow made from a large pale circle blended to a small bright one, or a stripe of colour that fades from one hue to another without visible bands.

Specified steps lets you say exactly how many objects sit between the two ends. Use it when the count matters: twelve rungs on a ladder, nine fence posts between two end posts, or a row of evenly spaced dots for a dotted rule.

Specified distance sets the gap between each step rather than the count. If you later stretch the blend, more steps appear to keep the spacing the same, which suits patterns where the rhythm matters more than the total.

Easing the steps and the colour

Even spacing is not always what you want. Vectornation has easing presets for both the steps and the colour, so the in between objects can bunch up towards one end, or the colour can hold for longer before it changes. Easing the steps is a quick way to suggest perspective, with shapes crowding together as they recede. Easing the colour makes a shaded form look rounder, because light rarely falls off in a straight line.

Try the presets on a simple pair of circles before using them on real work. The effect is easiest to judge when there is nothing else to look at.

Spines: the path a blend follows

By default a blend runs in a straight line between its two objects. That line is the spine, and you can swap it. Draw any path, select it with the blend, and replace the spine, and the steps now follow your curve. This is how you lay a string of beads around a necklace, a line of footprints across a page or a chain of letters around a circle.

Reverse the spine when the steps run the wrong way along the path, for example when the large end of a tapering blend is at the start of a curve and you wanted it at the finish. Reversing swaps the order without you having to rebuild anything.

Building a blend in a good order

Set up the two end objects carefully before blending. Same number of points, similar structure and a matching start point give clean in between shapes. Very different shapes still blend, but the middle steps can twist in ways that look accidental.

Decide early whether you need smooth colour or a counted number of steps, as they produce very different looks. Then add the spine, then easing. Working in that order means each change is easy to judge.

Because the blend stays live, you can keep adjusting the end objects. Recolour one end and every step follows. Scale the far end down and the whole run tapers. That is often quicker than redrawing, and it is the main advantage of blending over copying objects by hand.

When a blend is the wrong tool

A blend is about steps between two things. If you want one object repeated in a perfect grid with no change, a plain copy and repeat is simpler. If you want a smooth fill across an area, a gradient is usually lighter and easier to edit. Keep blends for the jobs where the in between shapes themselves are the point, such as shading built from rings, transitions between two silhouettes, or rhythm along a curve.