How to achieve a smooth canvas with molding paste

[@beedee4427]

I work in watercolour but not on paper (very much). I work on Aquaboard (either the Ampersand ready-to-go or ones I make myself with watercolour ground on masonite board) or I prep canvases using an inexpensive filler from the hardware store. The larger the canvas, the larger the metal scraper (meant for plastering walls). I generally do one coat of filler then sand down using a little mouse sander before applying three or four coats of watercolour ground, applied using a smooth (gloss) paint roller.

[@jclosestudio]

Interesting! I do have some Aquaboard somewhere, but haven't actually tried it yet. Do you apply the filler quite thickly with the large metal scraper? Have you had any problems sanding holes into the canvas?

[@beedee4427]

@@jclosestudio Hey! The filler I only apply quite thinly but might end up doing a couple of coats to get the smoothest surface possible. I actually thought about the process a bit more when I read your question and realised that I actually just use a sanding block with a smooth sandpaper to sand the filler, mainly to get rid of the ridges the metal scraper makes. I then add a couple of layers of white, water-based house paint for my first couple of layers after the filler. Then I sand back with my mouse sander and add three coats of Daniel Smith Watercolour ground. I then re-sand until I'm happy with the finish. You can achieve either a cold press or hot press finish this way. It's a big process but you can achieve a lovely finish, tailored to your preferences. The reason I buy canvases is that you can buy some reasonably cheap, ready framed (cradled) canvases in sizes much larger than any Aquaboards. Aquaboard is expensive to buy, especially if it's on a cradle. If you didn't want to go to the expense of watercolour ground then a similar effect can be made with just several layers of the house paint. Of course, the way the paint and water interact on this surface is a little different to the watercolour ground but it works perfectly well. It's all a matter of experimentation really. Also, I'd advise doing this with at least 3 or 4 panels at a time to make it worth while. Of course, if you're working on Masonite and making your own Aquaboard, then you just cut out the filler stage of the process as you've already got a perfectly flat surface. Hope that helps. Any further questions, just shout out 😎👍🏻

[@jclosestudio]

@@beedee4427 So helpful, thanks for sharing BeeDee! I might give it another try. Does sound like a lengthy process, but probably worth it.

[@janinafisher101]

Like you, I love painting on the smooth surface of wood. But the quickest solution I have found it to put 3 thin layers of gesso on, and sand in between each. You can sand with a coarser sandpaper the first two times, and then with coarse and then fine sandpaper for the final layer. You end up with a nice smooth canvas. I buy "sludge" gesso from my art supply store which is grey and cheaper, and then if you desire you can use a white, higher quality gesso for the final layer. Though I think if you're going to paint dark colours on first, the colour won't make as much difference.

[@jclosestudio]

That is a fantastic tip, thank you so much Janina! I will have to try this. I’ve used the Tri Art sludge gesso before. Is that the one?

[@janinafisher101]

@@jclosestudio I put it into a different bottle, but I'm 99% sure it's Tri-Art. Are you in Canada, too? That's a Canadian brand, made near where I live. It worked very well on a large canvas I was painting. It was actually a peony painting from Marianne VanderDussen's Painting Flowers in Acrylic course, and the gesso and sanding tips came from her in the course. It worked like a charm. The sludge gesso was very fine and very smooth. And a great price!

[@jclosestudio]

@@janinafisher101 Oh great! Did not realise it's a Canadian brand. I'm in the UK. I love that they use leftover paint that would go to waste and turn them into something new. Will give it a try!

[@polgara28]

Great tips! I hope you find the perfect solution. Thanks for sharing this video.

[@jclosestudio]

Thanks, Christie! I might just have to live with the texture 😄

[@ChantelleArts]

This is so satisfying, so many wonderful tips ☺☺

[@jclosestudio]

Thank you! A bit of a faff, but worth it if you have the patience 😂

[@lyn.k10]

This was helpful and came in a perfect time. I’m currently experimenting with pastes and grounds to alter 30 x 40 inch pre-primed canvases that I had purchased. I too am not fond of the gessoed canvas texture and prefer more absorption to achieve closer to a watercolour effect. I’ll move forward with light modelling paste. Thank you for your tips!

[@polgara28]

Liz Chaderton has some helpful tips for this very thing! I believe she uses watercolor ground, but not sure. Good luck!

[@lyn.k10]

@@polgara28 Excellent suggestion and exactly what I was after, thank you for sharing!

[@jclosestudio]

Hi Kris! Like Christie mentioned you could use watercolour ground. Fibre paste could also work.

[@xencage]

Apply thicker, and hit it with an orbital sander, and wear a dust mask!!!😊

[@jclosestudio]

Thanks, Kevin! Think I'd be worried I'll sand holes into the canvas 😄

[@xencage]

@@jclosestudio 😂 Yes, that could be a problem! But, a small electric sander with a light grit sandpaper could save you time and energy if you wanted to continue to pursue this. It can be very economical to buy large sheets of hardboard and have it cut into various size panels and seal and finish yourself, especially for large works. Cheers! Wonderful art and videos!

[@jclosestudio]

@@xencage Thanks, Kevin! Might try it on a practice piece first 😄.

[@Michou1012]

Tu peux, aussi, mettre du Gesso derrière la toile.

[@jclosestudio]

Thanks! Is that also to smooth the canvas?

[@Michou1012]

@@jclosestudio Oui. Choisir un Gesso de qualité. En général, ils sont plus épais.

[@jclosestudio]

@@Michou1012 Good point. I do find it still leaves quite a lot of texture still, but it will definitely help.