关于友情的英语文案如下：

1. A faithful friend is hard to find. 知音难觅。

2. A friend in need is a friend indeed. 患难见真情。

3. A friend is easier lost than found. 得朋友难，失朋友易。

4. A friend is never known till a man has need. 需要之时方知友。

5. A friend without is a treasure, a brother is a comfort, but a friend is both. 父亲是财富，兄弟是安慰，朋友兼而有之。

6. Friends are like fiddle-strings, they must not be screwed too tight. 朋友像琴弦，不能太拧紧。

7. Without a friend the world is a wilderness. 没有朋友，世界就等於一片荒野。

8. Between friends all is common. 朋友之间不分彼此。

9. A near friend is better than a far-dwelling kinsman. 远亲不如近邻。

10. All the splendor in the world is not worth a good friend. 世间一切荣华富贵不如一个推心置腹的朋友。

11. A faithful friend is the medicine of life. 忠实的朋友是人生的良药。

12. Prosperity gains friends ,and adversity tries them. 繁荣带来朋友，逆境考验他们。

13. Admonish your friends in private, praise them in public. 在私底下要忠告你的朋友，在公开场合又表扬你的朋友。

14. You the real friend who walks in when the rest of the world walks out. 谢谢你是那位全世界都遗弃我时还在我身边的朋友!

15. Your forever friend lifts you up in spirits and makes that dark and empty world suddenly seem bright and full.你真正的朋友会让你振作起来，原本黯淡､空虚的世界顿时变得明亮和充实。

希望这些文案能够帮助你表达对友情的珍视和感激之情。