Saturday, January 21, 2012

Size Experiments: some results

Sized Paper: Lite size Left/Heavy size Right

I'll lead in with the results and discuss the nuances after.

I can detect very little difference in the prints printed on my heavily sized vs. lightly sized paper. The bigger surprise was that there was little difference on the paper that had NO size.

My experiments are with a paper called Hosokawa and is imported in Europe by Japico ( a wholesale paper importer). The booklet at the store where I bought it lists it as: 90%Kozo 10% pulp and weight 39g/M2.
(However--different sources list the same paper as having 20%-40% pulp and I expect the proportion has changed in the last years.) There are other papers listed in their catalog with heavier weights and higher kozo percentages that weren't available at my local store but would be worth trying to find or convince them to add/order. (I'd rather try sizing a 70g/m2 100% kozo paper...).

The store-side sizing test...( a small amount of saliva placed on a corner of the paper) shows that it is rapidly absorbed into a big wet spot---showing that the paper isn't sized. (Do this discreetly--the owners aren't keen on you touching the paper much less spitting on it...).

My first sizing attempt of this paper: 40g glue and 20alum to 1L water was unsuccessful. The paper stuck to itself and dried wavy, puckered and uneven.
There were however some decent pieces within the whole sheet and these I cut out and have used for this trial.
This is called HS (heavy size). There is a slight sparkle/glisten to the paper which means there is a little too much alum or it wasn't fully dissolved.(New Hosho paper--available from Woodlike Matsumura in Japan has similar sparkle).

My second sizing attempt used 14g Glue and 5g alum per Liter water.
Because in the second try I didn't size all the way to the end I have some strips that are partly sized on one half and unsized on the other.

HS is heavy size; LS is light size; NS is NO size.

Sized Paper LS Left/HS Right: light betaban block and bright yellow (2 impressions)

Sized Paper: NS (no size) Left/Light size (LS) Right (see arrows)

Multiple impressions(10?) Each sheet is 1/2 LS and 1/2 NS (see initials/arrows) Since these were registration mishaps--I printed them a little more aggressively after--darker colors/more layers to see what would happen.

Results Comments:
While printing, the unsized portion did tend to pill/pull up a little bit but as I continued printing this was less of an issue and by the end at 10-11 impressions it was still printing ok. The unsized portion is perhaps a little less brilliant/vibrant. In the half LS/half NS you can see a line of demarcation so there is a difference but it would be hard to tell which was which if they were unlabelled.
In the top photo; the dark cherry red background has at least 5 layers of printed pigment--that is a fair amount of printing for a light-weight paper but it tolerated it well. (light yellow beta ban;carmine twice;cad red/carmine mix once; pale green wash once;keyblock).
The heavy sized paper seemed to allow the pigment to rest a bit more on the surface but that was more noticeable in the first few impressions (see the yellow arrows) but there was little difference at the end. It didn't resist the pigment at all and I had no trouble printing on it (there was no resist).
This is a lighter paper than I usually use. At 39g/M2 it is fairly transparent and soft and in the first impressions it was probably a bit too damp. I'm not sure if I could handle a bigger sheet when damp. The small size of this sample and the small paper size (4" x 8") and the fact that I was intermittently switching from different sized papers may have altered the results; a bigger sheet might have revealed differences not visible on small printed surfaces. The unsized paper printed surprisingly well and I expect it would be serviceable if I keep the board/printing fairly "dry".

P.S. I did the saliva test again once the paper was little gob of spit didn't absorb at all in the LS and HS portions of my printed paper--but got soaked up instantly in the NS portion.
P.S.S. I also sized a piece of Japanese Hosho (probably 100%pulp) from a different store--it tried to fall apart as I was sizing it but once sized (LS) it printed ok too. See photo below:
LS Japanese "Hosho" content unknown but looks like 100% pulp/sulfite


  1. Thinking things over:
    The biggest hurdles are:
    Getting the size (any recipe/ration) on the paper smoothly.
    Getting the paper to dry slowly and evenly to avoid buckling/puckering.
    These tasks are probably more important than the exact recipe/ratio.
    As there are MANY different size recipes with different quantities of Glue/Alum--and given that in theory, every paper in any season might benefit from more or less glue or alum...
    I suspect that the ratio/exact amoount is probably not that important.
    Too much alum will affect the longevity of the paper making it more acidic.
    Too much glue might make the paper too hard to print on.
    Even unsized paper if it has a high kozo content and is smooth/strong enough can be printed on and probably should be tried first?

  2. Looking over the little prints again in good light, the unsized portions are definitely a little more "fluffy", I can see paper fibers that have been disturbed in printing/pulling the sheets off the block. On the same sheets the portion that was sized is smooth and shiny and does not appear damaged by printing.