Preparation of Picture Canvas

[George O'Hanlon]

Changes in atmospheric humidity affect not only canvas but collagen glues as well. The issue you experience with the canvas is most likely caused by changes in relative humidity. This is an excellent demonstration why artists should be painting on rigid supports.

[Kakwirakeron]

Yes but what about the push pull of painting on a stretched canvas? There's such a particular response to the brush pressure of stretched linen that you don't get from the hard surface. It is a tactile preference I realize. Couldn't one paint on a stretched linen then transfer it to a solid substrate after?
Meantime though, have you any suggestions. My last batch of portrait linen required my re-stretching three times. One other point about my linen issue. The heat is on now where I live and it is dry...shouldn't it tighten under this circumstance?

[George O'Hanlon]

Yes, you can paint on linen and then mount it to a rigid substrate.

Humidity or moisture causes canvas to relax, while dryness causes it to become taut. There is nothing to do but re-stretch it.

[Kakwirakeron]

Well all seems well enough today, once thoroughly dried after a day or two, the linen snugged up enough to allow me to snug it up tight with keys. Today I knifed on a first light coat of lead onto my latest batch of linen. This part can be quite meditative...getting the layer just so.
I will be looking forward to receiving my order of Rublev white prime. I currently am using what I have of David Davis lead primer. It's quite thick, requiring a fair bit of elbow grease to get it just so. I got it to a somewhat creamy condition by thinning it with OMS. Even so, I have to really muscle it over the the surface of the canvas since it becomes honey-like in texture. But this seems to make it respond well to knifing.
Anyway thanks for the advice and empathy over my linen frustrations.

[Darren]

I've been self priming with Linen/RSG/Lead on stretcher bars since 1989 and I've never had a dry canvas go slack. In Minnesota (as well as Florence when I was there) we have a mix of very humid and very dry depending on the season. In light of that I think my canvases are exposed to extreme conditions.

On second thought, I did have an 8 foot by 10 foot canvas that showed some waviness in one corner. This was in Florida and I had to restretch that corner after the fact. My thinking at the time (1993) was that the weight of all that linen and lead was pulling it down. Could have been the humidity though I suppose.

Based upon your description of your primer it's possible that your solution for the thickness is over or restretching the canvas as you apply the lead. You might try adding a little linseed or turps to thin the mix a bit. IMO lead primer should be a bit thicker than honey.

Of course we've all seen crystalized honey so perhaps that's a bad comparison. :D

[Kakwirakeron]

Originally posted by Darren:
I've been self priming with Linen/RSG/Lead on stretcher bars since 1989 and I've never had a dry canvas go slack. In Minnesota (as well as Florence when I was there) we have a mix of very humid and very dry depending on the season. In light of that I think my canvases are exposed to extreme conditions.

On second thought, I did have an 8 foot by 10 foot canvas that showed some waviness in one corner. This was in Florida and I had to restretch that corner after the fact. My thinking at the time (1993) was that the weight of all that linen and lead was pulling it down. Could have been the humidity though I suppose.

Based upon your description of your primer it's possible that your solution for the thickness is over or restretching the canvas as you apply the lead. You might try adding a little linseed or turps to thin the mix a bit. IMO lead primer should be a bit thicker than honey.

Of course we've all seen crystalized honey so perhaps that's a bad comparison. :D

Darren,
The slackness I have been experience is something I had not encountered in the past either, in the same environment. I live in the Montreal, Quebec area and we do get a mix of climatic conditions. When it first happened this summer it was hot and dry - it blew my mind. I sell native american drums, which have raw moose hide skin stretched over wooden frames. If you want to see a hydroscopic material, then raw moose hide is up there. What I am used to telling people is that the hide will go limp when humid and that heat is required to remove the moisture - the skin, then goes -shall we say - drum tight?
Imagine my confusion that the linen would go limp and wavey once the size dried. My August batch of canvas had to be restretched three times during the priming process. I should clarify that it wasn't an issue when the lead was applied.
As to the honey-like condition of my lead, the condition of it seems more thixotropic once it is laid upon the linen. I work it onto the linen in 6 inch sections until I have the entire surface covered.
At this point, if I attempt to sooth it with a brush with lengthwise and widthwise strokes it isn't cooperative. The primer will almost bead up. But it responds quite well to smoothing with my palette knife.
I do have one question, since you brought up the possibility of adding more oil - that is, would you recommend adding a bit more oil to each succeeding layer of primer? BTW Recheck your comments about the primer. I wasn't entirely certain about what you were attempting to convey. Thanks for your input Darren. I DO appreciate it. K

[Darren]

Wow, would I love to visit!
Let's see. I may have misunderstood what you originally said. I thought, incorrectly it seems, that the slackness occured after priming. My bad.

As for adding more oil to each succeeding layer of priming I think I'll defer to George. I don't add more myself.

[George O'Hanlon]

Originally posted by Kakwirakeron:
...would you recommend adding a bit more oil to each succeeding layer of primer?

Yes, you can, but it is not necessary as long as each layer dries hard.

[Kakwirakeron]

Originally posted by Admin:
</font><blockquote>quote:</font><hr />Originally posted by Kakwirakeron:
...would you recommend adding a bit more oil to each succeeding layer of primer?

Yes, you can, but it is not necessary as long as each layer dries hard. </font>[/QUOTE]Thanks to you both, Darren and George. The question about adding oil was, in part, prompted by Darren's statement but also some tidbit or other on someone's website about priming. I had never heard this before but thought to ask anyway. K

[Kakwirakeron]

George
I was preparing some of the genuine RSG size this evening according to the recipe provided on the site...that is until I realized I failed to properly read the procedure for adding the alum to the RSG solution. Instead of first adding it to and dissolving the alum in water I added it directly to the glues size, stirring it in well.
Will I suffer any dire consequence if I go ahead and use the size as I have prepared it? Thanks.