From: Peter Fredrik (pete@fotem.demon.co.uk)
Date: 02/09/01-05:40:45 PM Z
Sarah Van Keuren wrote:
>
> It was BFK Rives paper. I had no idea there could be shrinkage, using hot
> water, of nearly 1/4 of an inch within a 14 inch stretch along the length of
> the paper and no shrinkage at all in the 10 3/4 inch width.
>
>
>
> This substrate problem seems like a tough one to resolve.
>
> Sarah
This is why I published my series of tests conducted five years ago. it seems
that this result is almost identical to my own --:
So I Continued paper testing this time trying out the following papers
a)Fabriano Artistico 200gsm [control]
b)Ingres Fabriano 90gsm
c)Hammer 4r 180gsm
d)Goldline Lanaaquarlle 185gsm
e)Rives BFK 200gms
f)Hunni 300gms
Each paper sample was soaked in cold water for 10 mins then dried with a hair
dryer. In each case the sample stretched beyond the original size when wet
then shrunk back smaller than the original size when dried, by the following
percentages.
a)0.33% [ control ]
b)1.00%
c)0.33%
d)0.33%
e)0.33%
f)0.33%
Which in the case of a) to f) was the same even though the paper weight was
very different
Although most of the papers seemed to follow a similar pattern, b) was the odd
man out. This paper was very thin and designed to be used as a paper for contie
crayon and chalks not really suitable for our processes it did stabilize but
kept moving around slightly.
Conclusion
Most papers shrank to the same extent independent of paper weight grain
direction thinner
papers expand and shrink to a greater extent and are more fragile ,however the
final shrinkage was the same,
I will freely admit that this is only starting point and the grain direction
should be taken into consideration
with some papers whilst being of no importance with others., also the soak time
needs to be evaluated.
However I firmly believe if the paper is submitted to a three stage cycle of
soak /dry it will reach dimensional stability when bone dry. .All I am
saying is in IMHO preshrinkig is the way to go and none the responses so far
have convinced me otherwise.
Pete
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