On Nov 21, 6:02*pm, "The Henchman" wrote:
Tight budget, and I'm a novice diy'er.

My wife wants my to build a wall to wall bookcase that is floor to ceiling.
...make everything out of MDF which is cheep, easy to treat
and easy to by decorative faces and mouldings for.

For shelves, MDF is terrible (it sags with moisture changes), and
plywood is second-rate. Solid wood is best.
For case sidewalls, floor-to-ceiling, solid wood is expensive and
plywood is tougher (won't split). MDF is least capable of taking
the hardware pins or brackets or whatever to support the shelves.
For a back to the case, MDF is fine.

Instead of buying decorative facings, one usually chooses an
attractive wood grain for plywood, or uses a paint treatment on
less attractive woods (maple, birch, softwood plywood are good for
painting).
A strip of solid wood on the edge of plywood is recommended for
appearance.