Creating intrincated lines patterns and shapes may seem like a very complex task, but it could be a very easy and straight forward process if you use the right tools. While most designers can think on making these backgrouns in Photoshop (which is also a great tool to make them) is easier to make them in Illustrator, with the advantage to have a vector file, thanks to the Blend panel. So today, I will show you how easy is to make a vector Abstract Lines Background in Illustrator using only the default tools and in less than 5 minutes.
Open Illustrator and make a new file at any size you want. In this case I will make mine at 1800 x 1200 px.
Select the Rectangle Tool (M) and draw a rectangle covering your whole artboard using any color you want. In this case, I will be using #262424.
Select the Pen Tool (P) or the Pencil Tool (N) and draw a curved path using the same color you've used for your background, which in this case is #262424.
With the Pen Tool (P) or the Pencil Tool (N) still selected, draw another curved path using any color that you wish, in this case I will set my stroke color to #808183.
Select both paths and go to Object > Blend > Make.
Go to Object > Blend > Blend Options. Under "Spacing" select "Specified Steps" from the dropdown menu, set a value of 80 and click OK in the Blend Options window.
With the lines already made, let's add a simple back figure to make it more appealing. Select the Ellipse Tool (L) and draw a circle in the middle of your artboard as shown.
With the circle selected, go to Window > Swatches.
In the Swatches panel, select the "Super Soft Black Vignette".
Lastly, select both the circle and the background rectangle and go to Object > Arrange > Send to Back.
Now that you've learned how to make an Abstract Lines Background in Illustrator, you can easily modify the path and the color without making the whole process again. Just select the path you want to modify with the Direct Selection Tool (A), move the anchor point to any location that you want, and easily change the stroke color in the swatches panel to get a new background in less than 2 minutes.