1. Open the picture to be composed in ps, and press Ctrl+J to copy the background layer.
2. Select "Custom Shape Tool" in the left toolbar, set it to path mode, and select your favorite pattern border in the shape drop-down box.
3. Hold down the left mouse button and drag out a border in the picture, and click the "Select" button.
4. Create a boundary selection as shown in the figure below.
5. Select "Fill" in the menu bar "Edit" to fill the lace border with white.
6. Select "Rectangular Box Selection Tool" in the left toolbar, click "Add to Selection" button, select the edge in the picture, and press Ctrl+delete to fill the background color (set the background color to white in advance).
7. Press Ctrl+D to cancel the selection and complete the boundary operation.
The above is a tutorial for ps to make border patterns.
How to use PS
Click the Photoshop icon to open the software, click the file in the upper right corner, and then click Open. Find the software to open in the folder. The file must be in image file format. Open the file and you can use Photoshop to process it. Complete the steps, pay attention to save the processed photos to prevent them from being lost. Specific operations have corresponding specific usage methods, which can be found by consulting books and the Internet.