[hakonsbakken]

There are several resources on this site:

https://paintingbestpractices.com/oil-painting-durability-best-practices/

https://paintingbestpractices.com/excessively-thinning-oil-paint/

https://paintingbestpractices.com/oil-painting-practices/

https://paintingbestpractices.com/yellowing-of-oil-paint/

I also recommend the Painting Best Practices course. It is comprehensive and you get to ask all your questions. 🙂

paintingbestpractices.com

Ensuring Art's Longevity: Strategies for Durable Oil Paintings

Discover key strategies to enhance oil painting durability. Learn how the right pigments, techniques, and care can preserve your artwork for generations. Find out more.

[hakonsbakken]

From your text I read that the yellowing happens in spots? In that case maybe it is more due to something else than the oil? Darkening/yellowing from darkness will generally affect the whole surface, but be more noticeable in the light areas.
Driers and resins yellows at a faster rate than oils, and is as far as I know permanent, but I am no expert.

[hakonsbakken]

Hi Luca
I think I can answer a few of these.

1. Yes, nothing wrong with oil priming over acrylic gesso. It would be very similar to applying oil paint over acryllic gesso. Also check the manufacturer’s guidelines.

2. I clean my brushes in oil (no clove), then soap and water. I would not add clove oil, since that would need to cleaned out of the brush before using it again. It does not take a lot of clove oil to significantly extend drying time of your paint. Plus I don’t like the smell. Pure oil would be ok, but I prefer clean, dry brushes when I need one. I would choose linseed oil, since that is the most common oil used in oil paint.

3. I will let someone else discuss this..

4. After sanding, remove the debris with a suitable lint-free cloth. There is also a recommendation regarding the type of sandpaper to use, but I don’t recall the details right now.

5. Painting over a dried (hard-dry) painting can be done after the surface has been cleaned of any dirt. You may sand or scrape the surface to remove ridges, but that is not required. Clean after. See also pt. 6 if the intent is to completely change the design. It is not considered best practice to prime on top of layers of paint. Then it is better to find a new surface.

6. Painting over a white ground is considered THE best practice since oil paint tend to become more transparent over time.

[hakonsbakken]

If you glue primed canvas or linen or another support to your panels, you typically don’t need to size.

Under a lead oil ground you should definitely apply a coating to prevent oil from the ground and paint to penetrate the wood. I believe one coat of Rublev Fluid Medium is sufficient (for oil, two for acrylic).

[hakonsbakken]

Michael Harding makes an N5, but it used to have zinc white in it. That could have changed since I last checked. Apart from that you could reach out to Graydon Parrish, who does a lot of color experiments, including measurements.

[hakonsbakken]

You asked if people have mixed and measured. A few have done both. Graydon is one of them.

Personally, I mix and tube my own N3 and N7 in addition to the N5 from MH. I typically use chremnitz white, ivory black and raw umber or raw sienna to mix. I measure against a Munsell grayscale. It is accurate enough for me.

[hakonsbakken]

I mix my own Regalrez, that has been really easy to do. With proper drying time and cleaning before varnishing, the results have been very good. Also, lead oil grounds have improved my results over the acrylic primers/gessoes.

Finding a solvent for the Laropal has been more cumbersome..