Single width, hollow.
┌─┐	)0lqk
│ │	)0x x
└─┘	)0mqj
┌─┐
│ │
└─┘

Single width, single fill.
┌┬┐	)0lwk
├┼┤	)0tnu
└┴┘	)0mvj
┌┬┐
├┼┤
└┴┘

Double width, hollow.
┏━┓	)0   
┃ ┃	)0   
┗━┛	)0   
╔═╗
║ ║
╚═╝

Double width, double fill.
┏┳┓	)0   
┣╋┫	)0   
┗┻┛	)0   
╔╦╗
╠╬╣
╚╩╝

Double width, single fill.
┏┯┓	)0   
┠┼┨	)0 n 
┗┷┛	)0   
╔╤╗
╟┼╢
╚╧╝

Single width, double fill.
┌┰┐	)0l k
┝╋┥	)0   
└┸┘	)0m j
┌╥┐
╞╬╡
└╨┘

Single width, mixed fill (double horizontal, single vertical).
┌┬┐	)0lwk
┝┿┥	)0   
└┴┘	)0mvj
┌┬┐
╞╪╡
└┴┘

Double width, mixed fill (double vertical, single horizontal).
┏┳┓	)0   
┠╂┨	)0   
┗┻┛	)0   
╔╦╗
╟╫╢
╚╩╝

Double horizontal, single vertical.
╒╕ 
╘╛ 

Double vertical, single horizontal.
╓╖ 
╙╜ 

VT-102:  http://vt100.net/docs/vt102-ug/table5-13.html
Unicode: http://www.unicode.org/charts/PDF/U2500.pdf