Digital BW, The Print

>Whatever. It's a good bang for the buck. ...

Yes, that we can mostly agree on. 

>I think there's a big difference between acid neutral and acid free.

I'd rather have acid free, but a well-processed alpha cellulose paper may
still have a tiny residual of lignin (the main "acid reserve" in otherwise
well-processed wood-based papers) and also have enough buffer to offset that
lignin "forever" (well long enough, anyway).

> Acidic neutrality is achieved by adding buffers that, over time, 
> lose their effectiveness and the paper once again becomes acidic.

It's a matter of degree, apparently.  The numbers I've heard are that the
paper must have less than 1% lignin and more than 2% buffering.  Assuming
this is true and a valid standard, there is no way to easily measure the
amounts of each.

> This is not the case for acid free, although over time, with 
> exposure to an acidic environment, acid free paper will also 
> deteriorate.

Yes, the best is an acid free (cotton) paper which is also buffered.

> Acid neutral paper uses a wood fiber component and acid is 
> used to break down the fibers,

I think there are acid-free processes for wood paper, but even if there are,
if the lignin is not totally removed there will be acids produced by the
lignin as it oxidizes.

> whereas, acid free is generally made from cotton rag fibers and 
> acid is not used to break down the fibers when making archival papers. 

Cotton is apparently almost pure cellulose, which is "acid free."  Cellulose
is said to be the largest single component of the biosphere.  Number 2,
however, is lignin, which is the stuff that allows trees to stand up
straight.

>While Kirkland papers may be acid neutral I seriously doubt 
>they are acid free

I assume they use wood-based paper (as do some very good papers, including
good wet process darkroom papers).

> and I would not consider them as archival.

The best we can do cheaply is test the current acidity.  Sadly, this does
not tell us the percentages.  Some outfits will tell you whether their paper
meets the 1%/2% criteria, in part because it may be important for large
purchasers like governments and businesses that want their files to last.  I
wonder if Costco would respond to the question.

Paul
www.PaulRoark.com