Bob,

Thank you for your response!

This assumes you want 4" wide trim as you state in your post below.

That's my initial plan, simply based on available 1x4 lumber. But, I'm
certainly not fixed on that size. Our current home has trim that is 1-3/4"
wide and only 1/8" thick (yep, a mobile home), so anything has to be an
improvement over this (which actually looks halfway decent).

Using a 2x4 (nominal 1-1/2" x 3-1/2") or 2x6 (nominal 1-1/2" x 5-1/2")
isn't going to work out as you think. The kerf of any blade (regular
or thin-kerf or bandsaw) will reduce the thickness of each piece and
it will be less than 3/4".

I figured by the time I ripped the 2x4 in half and planed it smooth, I
would end up with trim that was approximately 1/2" thick. Maybe not a
"standard" trim size, but certainly usable. In some ways, I actually think
I would prefer the slightly thinner trim.

If I'm willing to accept a smaller width as well, I could rip a 2x6 in
half, then rip each half in half. This should provide four pieces of trim
from each board that is at least 2" x 1/2" after planing. That's a little
small, but still usable for it's purposes of covering gaps and whatnot (and
larger than the trim we have now).

Ripping construction grade lumber usually results in a lot of waste
due to stress being released (bowing, cupping, twist) not to mentioned
the shrinkage factor after the trim dries out - next year. Most
construction grade lumber is dried to only 15-20% MC. Don't know
where you live but as the trim dries it has a high probability that it
will shrink, split, etc.

Those are some of the reasons I've been hesitant to go with the framing
lumber approach. Still, I've had pretty good luck using boards I ripped
from off the shelf framing lumber. I've done several projects using trim
sized boards, and not one has split, cracked, or shrunk noticeably in the
last several years. But, it tends to stay fairly wet here in the Pacific
Northwest...

I think your waste will still be at 25%.

A cedar 1x4 costs somewhere around $6 to 8$ locally for an 8' board (don't
recall the actual prices now). As you mentioned, I could probably get pine
for around $5.

An 8' KD 2x4 at $3 would yield two boards, or about $1.50 per 8' trim
board. Even if half turn out to be unusable, that's still $3 per board as
opposed to $5 for pine.

Then again, I'm paying about .26/ft for my 1x6 T&G cedar (#3), or about $2
for an 8' board. Ripping the tongue and groove off, leaves me a board that
is at least 4" wide, and just under 3/4" thick. Pretty decent for trim.
But, the cedar has a lot of knots and stuff that would probably increase
the waste percentage considerably.

I'll probably have to try a few approaches and see what is going to be the
best compromise of cost and labor.

Thanks again for the input. I appreciate it.

Anthony