Re: two questions about gum

[Katharine Thayer <kthayer@pacifier.com>]

On Sep 25, 2007, at 4:54 PM, Katharine Thayer wrote:

> (1) Charles,  this makes sense; there's enough size in most  
> watercolor paper as manufactured to keep the first layer from  
> staining, but subsequent layers on unsized paper (depending on the  
> paper) could well stain.
>
> (2)  I don't know that there's a rule of thumb for how to deal with  
> this; people do whatever works for them, I suppose.   If cutting  
> the exposure time works, great.  I can imagine that a drastic  
> reduction in exposure might a similar effect to a reduction in  
> pigment, but I've never tested that.
On reflection, I doubt the effect is the same;  with underexposure it  
seems like you would be more likely to lose highlights than you would  
with a reduction in pigment.