At first, I shoud consider what kind of material is suitable for masking.(There will be 2layer for this board. Horizontal line will be on 2nd layer.)
Mask need to be insulator and also thermostable as using soldering iron.
After some experiments, I selected masking tape. It's easy to cut by using vynyl cutter or normal design knife.
Regarding circuit, I referred Neil's "hello.array.44.2.cad" and learnd what is Charlieplexing.
Without using Charlieplexing, there will be too many lines and it's too complicated.
I used eagle to draw circuit but it seemed quite bigger than original Neil's board. I need more and more practice to make small and integrated PCB.
Soldering horizontal line was a little challenge for me. At first time I used piano wire, as soldering was not good enough, some LED lit and some didn't. I lerned wiring should be thin and easily welding, such as tinned wire.
As for the code, I referred Neil's one and burned by Arduino IDE.
Using AVR ISP mk2 was quite useful because ISP's led indicator taught me wheather there is any error on the board.
I want to add this status LED's function in my ISP board in the future.