First, it is suggested that the UI Adobe, such as Illustrator Sketch.app,, can be used as the vector drawing software. If the use of PS and other bitmap processing software, it is recommended as far as possible the use of vector mask. I myself is a person who likes to use Illustrator Adobe as a hobby. At present most GUI, including UI iOS, the shape of the control is very simple graphics. As a vector creation software, AI has a natural advantage in the processing of shape and curve. Such as in the AI, you can adjust the rounded corners of the rectangle. AI supports multiple filling, and multiple strokes. If an object can be simulated with a horizontal gradient filling in the bottom of the bottom, and a vertical direction of the filling to simulate the illumination, the PS can only be achieved by drawing two separate vector objects. CS 5 join aligned to the pixel grid and CS 6 adding gradient stroke function can be said AI is very suitable for sophisticated UI design, even with AI do UI design may is more convenient than with PS. In addition, the use of vector rendering software for the creation of another big advantage is that it is easy to deal with the changes in demand, such as changing the curve shape, rounded size, output size, etc.. In the past, after the release of iPhone 4, in order to adapt to the @2x resolution, a lot of designer. Now, although the iPad, iPhone have a retina screen, but no one can guarantee that the future of Apple will launch resolution again doubled Retina Super screen devices, the need to use UI resolution of @4x resources. I used to do iOS development, it has experienced such a thing: in the past, the Apple provides a App to be used in Store iTunes display icon size is 512 x 512 pixels. But when I uploaded App, it was found that the use of 1024 x 1024 resolution of the icon. Because I is AI icon directly to vertical scaling 200 re export a fix, the minutes of the thing. In addition, because AI is a vector drawing software, file storage is a geometric information rather than a bitmap pixel distribution information, so many times, the source file size of AI storage is smaller, and the file size and resolution are not too much. Below this icon is what I do with AI, the source of the space for the file is how large it? The answer is that the 516 KB. is the most important, the 516 KB I can output into any size, and not worry about the emergence of the phenomenon of 'mosaic'. To sum up, it is recommended to do UI, icons, etc. using AI and other vector rendering software to do, or use the PS vector mask tool. PS: why didn't you feel PS and use AI's portrait with Vim and Emacs as the people despise each other? Show all Source.