You’re going to love using the Curvature Tool and the Blend Tool to create these beautiful line graphs! In this Adobe Illustrator tutorial, we’ll build a simple colorful analytics dashboard style line graph with a blended gradient that fades in and out based upon the curve in the line chart. We’ll use the Grid tool, the Curvature tool, Gradients, the Curvature tool, Direct Selection, and Opacity changes to create a beautiful and colorful dynamic effect.
Creating the Grid
Grab the Rectangular Grid Tool and click once to create a grid. The grid that works for the size of my document is a grid that is 1500px wide and 900px tall and 9 Horizontal Dividers and 0 Vertical Dividers. I used the Direct Selection tool to click on the vertical paths on each side of the grid so we’re left with just 11 horizontal lines. I set a stroke color that very nearly blended with the background but was still noticeable so we have a beautiful set of lines that are subtle.
The Curvature Tool to Create Great Line Graphs and Curves
Right beneath the Pen tool is the Curvature tool. Grab this tool and draw out a sweeping line where we want our graph to appear and set the stroke to 5pt and set the color to white. Copy this line to the clipboard by hitting Cmd/Ctrl + C and then open the Gradient panel and click on the gradient thumbnail to apply a gradient to the stroke. Change up the colors of the gradient for that stroke to whatever you want.
Duplicating, Blending, and Fading with the Blend Tool
Hold down your Alt/Opt key and drag a copy of the stroke downward below the area where the line graph will reside. Double-click on the Blend tool icon in the toolbar and choose “Specified Steps” from the drop-down menu and set the number of steps to 300 or so. Select each of the paths with the Move tool by holding down Shift and clicking on both paths and then grab the Blend tool and click on a corresponding anchor for both paths to create the blend between both paths.
Adding Contrast Between Line Graph and Colored Blend
Open the Layers panel and open the blend up by clicking the little arrow in the Layers panel and select the path that is the duplicate path at the bottom of our blend by clicking on the little circle to the right of the layer and then open the Transparency panel and reduce the opacity of this path to 0% opacity. This will auto update the blend to go from the color to complete transparency. Also, paste in that solid white stroke we copied to the clipboard earlier by going Edit>Paste in Front and set the layer to Overlay in the Transparency panel and then select the entire blend in the Layers panel by hitting the little circle for the blend and reduce the opacity of the blend to 50%. As with each of these tutorials, it’s best to check out the video at the top of this article to see exactly what I do and how you can do that same thing.
Wash, Rinse, Repeat to Build Out Effect
Once you have your color blend all laid out you can repeat the process above and start layering on additional lines for our graph. You can go and select the entire blend in the Layers panel and use the Move Tool (V) and scale or widen or move the entire blend around to change the way the blend looks.