The Appearance configuration panel allows you to control aspects of PuTTY's appearance.
The "Cursor appearance" option lets you configure the cursor to be a block, an underline, or a vertical line. A block cursor becomes an empty box when the window loses focus; an underline or a vertical line becomes dotted.
The "Cursor blinks" option makes the cursor blink on and off. This works in any of the cursor modes.
This option allows you to choose what font, in what size, the PuTTY terminal window uses to display the text in the session. You will be offered a choice from all the fixed-width fonts installed on the system. (VT100-style terminal handling can only deal with fixed- width fonts.)
The "Window title" edit box allows you to set the title of the PuTTY window. By default the window title will contain the host name followed by "PuTTY", for example server1.example.com - PuTTY. If you want a different window title, this is where to set it.
PuTTY allows the server to send xterm control sequences which modify the title of the window in mid-session. There is also an xterm sequence to modify the title of the window's icon. This makes sense in a windowing system where the window becomes an icon when minimised, such as Windows 3.1 or most X Window System setups; but in the Windows 95-like user interface it isn't as applicable. By default PuTTY's window title and Taskbar caption will change into the server-supplied icon title if you minimise the PuTTY window, and change back to the server-supplied window title if you restore it. (If the server has not bothered to supply a window or icon title, none of this will happen.) By checking the box marked "Avoid ever using icon title", you can arrange that PuTTY will always display the window title, and completely ignore any icon titles the server sends it.
If you enable this option, the mouse pointer will disappear if the PuTTY window is selected and you press a key. This way, it will not obscure any of the text in the window while you work in your session. As soon as you move the mouse, the pointer will reappear.
This option is disabled by default, so the mouse pointer remains visible at all times.
PuTTY allows you to configure the appearance of the window border to some extent.
The checkbox marked "Sunken-edge border" changes the appearance of the window border to something more like a DOS box: the inside edge of the border is highlighted as if it sank down to meet the surface inside the window. This makes the border a little bit thicker as well. It's hard to describe well. Try it and see if you like it.
You can also configure a completely blank gap between the text in the window and the border, using the "Gap between text and window edge" control. By default this is set at one pixel. You can reduce it to zero, or increase it further.