Can I use ordinary office inkpad for calligraphy stamp?

It's different. Calligraphy inkpad is easier to change, full of color, and will not be scattered, while office inkpad is an ordinary oily inkpad, which will be scattered when covered with rice paper, will not be preserved, and is not easy to mount. Of course, beginners can use ordinary inkpad (that is, the work has little value and price for the time being), but it doesn't hurt to practice.