Why is it so important to design using a pen? There is direct connection between the BRAIN and the PEN.
Designers love their software. From using Gimp to Photoshop, designers spend hours crafting on the computer. Unfortunately, many designers neglect an important design tool: sketching by hand with pen and paper. Drawing by hand can bring clarity to the design process and help designers generate ideas, get organized, and visualize their concepts.
Computers speed up the design process, increasing productivity. However, sometimes we work so fast that we don’t allow our brains time to develop new ideas. Sketching on paper forces you to slow down and your brain naturally fills this added time with new ideas, concepts, and design directions.
This is also true for writing. If you are struggling to articulate an idea or come up with new copy for a marketing campaign, try writing by hand. The time it takes to write out a sentence by hand gives your brain space to work and often results in new ideas.
Another way sketching on paper helps you generate ideas is by helping your thoughts move from abstract to concrete. The mind can only hold so many concepts at once. Getting abstract design concepts down on paper allows your sketch to work as an “external brain” and lets your mind delve deeper into solving design problems at hand. Having multiple concepts sketched in front of you also lets you combine ideas while they are still in a rough format, leading to a greater variety of options than you would have been able to manage in your head.
text from http://webmarketingtoday.com