Creating slices in Photoshop can be a helpful technique when preparing images for the web. This approach allows you to divide a larger image into smaller sections, which can be exported as individual image files. This is particularly useful for web design and optimizing website loading times. Let’s explore how to slice images in Photoshop and why it might benefit your web projects.
First, open your image in Photoshop 2022 (Release 23.4.1 on Windows 11).
Create a new document if you’re starting from scratch. For this example, let’s use a 960x960px canvas with a white background. Ensure you set the color profile to sRGB IEC61966-2.1 and choose either 8 or 16 bit depth depending on your needs.
Next, divide your image into slices using guides. Go to View > New Guide. Set up a vertical guide at 50% and a horizontal guide at 50%. This will divide your 960x960px image into four equal quadrants, each measuring 480x480px.
Now, select the Slice Tool from the toolbar (it’s nested under the Crop Tool).
With the Slice Tool selected, click Slice From Guides in the options bar at the top. Photoshop will automatically create slices based on the guides you’ve set.
To export these slices, go to File > Export > Save For Web (Legacy).
In the Save for Web dialog, you might want to adjust the magnification to 50% or another suitable level to view all slices clearly.
Select all the slices you want to export. Click on the first slice, then Shift + Click on the remaining slices to select them all.
Under the Preset dropdown menu, choose your desired file format. For web graphics, JPEG High is a common choice for photographs and images with complex colors. While the original article focuses on JPEG, remember that slicing can also be beneficial for optimizing other web image formats, including GIFs, especially if you are dealing with animated GIFs where you want to control the optimization of different parts of the animation.
Verify that the Image Size still reflects your original dimensions (960x960px in this case).
Click Save and choose a destination folder for your exported slices. In the File name box, you can rename your files as needed. Photoshop will automatically append slice numbers to the filenames.
After saving, navigate to your chosen folder. You will find individual image files (in this case, four JPEG images), each representing a slice you created, and each measuring 480x480px.
To ensure perfect alignment and check your work, you can create a new 960x960px document with a white background. Then, go to File > Open and select all the exported slice images. Drag and drop each slice image into your new white document. Use the guides to help align them precisely. Alternatively, you can use File > Place Embedded instead of dragging and dropping.
Note: For consistency, it’s recommended to stick to either dragging and dropping or embedding files. Mixing methods might lead to slight inconsistencies in color or saturation between images, as observed in the original note. For best results, dragging and dropping generally maintains better color fidelity to the original image in this context.
By slicing your images, you can optimize loading times for web pages by allowing browsers to load only the necessary parts of a larger image. This technique contributes to a faster and more efficient user experience, especially when dealing with complex web designs or large visuals. While this example uses JPEGs, the principles of slicing are broadly applicable to various web image formats and optimization strategies.
