The Symbols feature in Sketch is an incredibly helpful and time-saving tool for repeating elements in your design. It’s primarily for UI designers who need to have consistent elements across multiple mockups, but it’s helpful for anybody who might need to use repeating elements.
Before we start the tutorial, you should make sure to add the buttons "Symbol" and "Create Symbol" to the toolbar by right-clicking on any part of the toolbar and selecting "Customize Toolbar" from the menu.
Why Use Symbols?
Say you’re making a UI mockup with a row of buttons that all look the same. Your first instinct may be to just duplicate the amount of buttons you need, but what if you need to go back and change something. Normally, you’d have to go and change every instance of the button, or make duplicates all over again. That can get a little tedious, especially if you find yourself making small changes here and there as time goes on.
In Sketch, Symbols are instances of a shape or group that are linked. Any changes made to one of them get made to all of them. This includes shape, size, color, anything you change about a Symbol will reflect in all other instances of that symbol.
Anytime you need to make an adjustment to a repeating element you can do so without worrying about keeping everything consistent. This not only saves time, but also saves you from making mistakes.
Creating a Symbol
Using Symbols is actually pretty easy, and starts very much like drawing any other shape in Sketch. In fact, it's the same exact process, just with a little extra step at the end.
Let's start by creating a rounded rectangle. (Reminder: you can quickly activate the rounded rectangle tool by simply pressing 'U' on your keyboard). We're going t give it a width of 160 and a height of 40. Turn off the border and give it a gradient fill of #40F5D5 to #299E89.
Make sure you've selected the shape we just created, then go up to your toolbar and click the button labeled "Create Symbol". That's it! You've created a Symbol! If you look to your layer panel on the left you'll notice a purple folder, that's the symbol you just created. These folders work in very much the same way as groups, which you can differentiate by the folder color.
Remember that no matter how many copies you make, you will be able to edit any instance of this symbol and have the changes be reflected everywhere, even in the original.
Creating new Instances
There are 2 ways to create a copy of your Symbol. You can use a Symbol anywhere within the document it was created in. That includes other art boards, and even other pages of the document. However, symbols do not work across documents so plan ahead when building your projects.
You could simply copy & paste your Symbol to create new instances, but there is another way that may be easier depending on your particular project. One of the buttons you should have added to the toolbar was the "Symbols" button. This button gives you a list of every symbol in your document. Every time you use "Make Symbol" on a shape or group, it's added to that list, even if you've deleted all instances of the symbol.
Click the "Symbol" button and then select the button we created from the list. A copy of the button will appear somewhere near or overlapping the original. Drag it and line it up underneath the original.
Editing & More
To edit your button, double-click on either instance on the canvas. From there play around with anything on the inspector panel and watch how the other button reflects the changes you've made to the selection. Try changing the radius of the rectangle as well as adding a drop shadow for even more depth.
Any shapes you put inside the Symbol's purple folder will be added to the symbol. Furthermore, groups can be turned into symbols by selecting the group and clicking "Create Symbol" in the toolbar. Try making symbols made up of multiple shapes.