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Drying oil is a vegetable oil that dry to a hard finish at normal room temperature. Such oils are used as the basis of oil paints, and in other paint and wood finishing applications.
they include linseed oil.

Drying oils
See also: Drying oil
Drying oils are vegetable oils that dry to a hard finish at normal room temperature. Such oils are used as the basis of oil paints, and in other paint and wood finishing applications. In addition to the oils listed here, walnut, sunflower and safflower oil are also considered to be drying oils.[175]

Dammar oil, from the Canarium strictum, used in paint as an oil drying agent.[176] Can also be used as a lamp oil.[177]
Linseed oil’s properties as a polymer make it highly suitable for wood finishing, for use in oil paints, as a plasticizer and hardener in putty and in making linoleum.[178] When used in food or medicinally, linseed oil is called flaxseed oil.
Poppyseed oil, similar in usage to linseed oil but with better color stability.[175]
Stillingia oil (also called Chinese vegetable tallow oil), obtained by solvent from the seeds of Sapium sebiferum. Used as a drying agent in paints and varnishes.[179][180]
Tung oil, used as an industrial lubricant and highly effective drying agent. Also used as a substitute for linseed oil.[181]
Vernonia oil is produced from the seeds of the Vernonia galamensis. It is composed of 73–80% vernolic acid, which can be used to make epoxies for manufacturing adhesives, varnishes and paints, and industrial coatings.[182]
Wikkipedia.

Linseed oil, extracted from flax seed, is one of the most useful natural oils. It is used as a preservative for wood, concrete, and an ingredient in paints, varnishes, and stains. As if that wasn’t enough, it is also used in soaps, inks, and in the production of linoleum!

Linseed oil is a slow-drying liquid with good preservative properties and water resistance.
Before the advent of modern preservatives and synthetics, it was commonly used as a stand-alone preservative for wood, natural (hemp) rope, and masonry, as a conditioner for natural boar’s hair paint brushes, and as an additive for oil paints. It was also valuable inside as a furniture finish and for wood floors.

Some of the problems with straight linseed oil, boiled or raw, are:

Sometimes linseed oil can take forever to dry… or stays sticky or doesn’t dry at all!! This is a nightmare situation that happens too often when linseed oil is applied either (1) too thickly, (2) onto damp materials or (3) when the temperature is too cold. Thinning linseed oil with turpentine can help somewhat, but even with thinning it is important to apply thin, multiple coats but allow each coat to dry before applying the next!
No UV (ultraviolet) light resistance… UV causes more damage to exposed wood than any other factor, destroying wood fibers and setting it up for attack by mildew, fungus, and insects.
Linseed oil is mildew food… Many vegetable oils are food products for humans… all vegetable oils are food products for mildew! Linseed oil is not completely denatured, so it can encourage rather than discourage mildew growth.
Linseed oil does not harden sufficiently to offer enough resistance to abrasion to be a suitable deck floor preservative… at least by today’s standards. Linseed oil has been used for interior wood floors, but it must be waxed for durability! Waxing an outside deck would be dangerous, even if you hang a “Slippery When Wet” sign!
Difficult to remove from wood… Multiple coats of linseed oil are gummy and difficult to remove fully for refinishing.

Boiled Linseed oil

“Boiled” linseed oil is not boiled. The actual boiling of some oils changes their drying characteristics, true. With linseed oil, though, it is the addition of certain solvents that causes linseed oil to dry more quickly, acting as if it were boiled.

These highlights were taken from this great article

Raw linseed oil can be used as a wood finish but it can take weeks for it to fully cure. It is for this reason that we use a polymerized linseed oil which is somewhat more viscous than raw linseed oil (making it more difficult to spread and apply) but dries considerably more quickly. The polymerization of the oil is accomplished by applying heat to the oil in the absence of oxygen. Be aware that this process produces a final product that is not the same as the “boiled linseed oil” that you might find on the shelves of home improvement and hardware stores. As counter-intuitive as it seems, boiled linseed oil has not been “boiled” or heated at all but instead has had petroleum-based solvents and metal driers added to it so that it supposedly behaves as if it was “boiled”. The most commonly used heavy metal dryer in “boiled linseed oil” is cobalt that is considered toxic. Additionally, a finish generically referred to as “Danish Oil” is produced by large paint manufacturers and contains some linseed oil but the majority of the components may be carcinogenic, petroleum-based ingredients such as Naptha, Mineral Spirits, and Dipropylene Glycol Monomethyl Ether.

Our linseed oil finish is 100% pure polymerized linseed oil that contains NO petroleum distillates, NO volatile organic compounds (VOCs) and NO heavy metal driers. The heating methods used to polymerize our linseed oil finish have been adapted from 18th to early 20th century varnish-making techniques while also using current technology and quality control measures to ensure a consistent and natural product. We have taken the approach that a simple, natural finish is safer for us to work with, as well as, provide customers with non-toxic furniture.

from Dapwood furniture site
Can you boil your own linseed oil?

interesting thread here.
Tung Oil

from eBay in a metal can with plastic lid.
Liberon Pure Tung Oil 1 L -014617-
Brand new
5.0 out of 5 stars – Liberon Pure Tung Oil 1 L -014617-2 product ratings
£27.00

Camellia Oil ( Tea Seed Oil )

Camellia oil, also known as tea seed oil  is the actual green tea oil. It comes from the seeds of Camellia sinensis, the plant from which all the tea is made. Tea seed oil is a wonderfully healthy in more ways than one. It is great for cooking, and from nutritional point of view. Tea seed oil is used in a number of beauty products. This oil has been used as a cooking for centuries in Southern China and they make many more uses with it.

buy from eBay

Japanese Camellia Oil – 240ml
Rutlands Part No. JP2100
Reviews (1)
Key Features
A well kept Japanese secret
Popular with the Samurai for protecting and cleaning their swords
Its very light, low viscous formula that does not dry or become resinous over time
Blended with paraffin oil it canb be used for lubricating, sharpening and rust protection
Simply spray on and wipe over the blade or tool
Ideal for protecting white or blue paper steel kitchen knives when not in use

Turpentine

Turpentine

turpentine
ˈtəːp(ə)ntʌɪn/Submit
noun
1.
a volatile pungent oil distilled from gum turpentine or pine wood, used in mixing paints and varnishes and in liniment.
2.
any of a number of trees which yield turpentine or a similar resin, in particular:

Turpentine (also called spirit of turpentine, oil of turpentine, wood turpentine and colloquially turps[1]) is a fluid obtained by the distillation of resin obtained from live trees, mainly pines. It is mainly used as a solvent and as a source of materials for organic synthesis.

Turpentine is composed of terpenes, mainly the monoterpenes alpha-pinene and beta-pinene with lesser amounts of carene, camphene, dipentene, and terpinolene.[2]

The word turpentine derives (via French and Latin) from the Greek word τερεβινθίνη terebinthine, the name of a species of tree, the terebinth tree.[3] Mineral turpentine or other petroleum distillates are used to replace turpentine, but they are very different chemically.Read more

Product description

Colour Name:500ml

* Size 500ml. * Pure Gum Turpentine. * May be used to dissolve Beeswax to make a wax polish. * Traditional thinner for alkyds, oils, varnishes, enamels and Artists colours. * Pure Gum Turpentine improves brushing qualities and cleans brushes, rollers, and spray equipment. * It may also be used to remove dirt, wax, and grease from surfaces before painting. * Solvent. * Low flash point. * Evaporates quickly. * Compatibility Can be used as a solvent with most oil based products.

ATLANTIS
ATLANTIS PURE GUM TURPENTINE
1 product review
£6.15
PRODUCT DESCRIPTION
We are delighted to have sourced this, the purest from of turpentine. Extracted from Portuguese marine pine trees (Pinus Maritima). Buy here

Driers

A dryer works by catalyzing or accelerating the curing and hardening of oil paint. Often, they are based on metals, and are sometimes called metal soaps or salts. In the process of drying, oil-based paints first absorb oxygen, then they form peroxide which decomposes. Driers accelerate this process

A short summary of drier catalysts:

1) Cobalt – the fastest, most active drier. Can cause wrinkling and color changes in light-colored paints.
2) Manganese – also very fast, but has a dark color which makes it questionable for use.
3) Iron – promotes rapid drying by polymerization. High content of iron in iron oxide colors accounts for their rapid drying time.
4) Rare Earth – useful under conditions of high humidity or low temperatures.
5) Lithium – sometimes added to other driers, most often alkyds.
6) Calcium – Performs well overall, often added during the pigment grinding process as an auxiliary dispersant. Basically marble dust.
7) Zirconium – Used with calcium as a replacement for lead. Has better gloss and color retention than lead, but may not do well under high humidity or low temperature.
8) Aluminum – Great polymerization and yellowing resistance without negatively affecting viscosity. Probably the number one drier in overall usage today in the form of aluminum stearate

read more here.

“Japan drier” is a common term for any oil drying agent that can be mixed with drying oils such as linseed oil and alkyd-oil paints to speed up “drying”. The name refers to “japannning”, a term for the use of drying oils as an imitation or substitution for urushiol-based Japanese lacquer. In the nineteenth century, Japan driers often were made with lead and manganese in a base of linseed oil, turpentine and natural resin. The resins used were copal, dammar, rosin and shellac. Today, most Japan driers consist of manganese in a base of linseed oil and mineral spirits.

Manganese is a primary oxidizing (active) drier. Used alone and in thick applications of paint it has a tendency to cause wrinkling. Manganese is generally used in combination with lead, zirconium, calcium or combination of these metals as a drying initiator.

Lead is an effective auxiliary driers when used in conjunction with active driers, such as manganese. Lead promotes the through drying of paint film. It improves the action of manganese drier and is used in conjunction with it and assists in the “through dry” of oil and alkyd paint.

DIRECTIONS
Add one drop per 5 ml (about 1 teaspoon) of paint. Suggested use levels should be verified with tests.

Physical Properties
Appearance: Dark brown liquid
Color (Gardner): Brown
Lead Content: 10%
Manganese Content: 2%
Non Volatile Content: 47%
Specific Gravity (@25° C., kg/L): 1.02
Viscosity (@25° C., Gardner): A1
HEALTH AND SAFETY
WARNING! CONTAINS: TURPENTINE AND LEAD. Exposure may cause skin and eye irritation. Overexposure will cause dizziness, drowsiness, headache, nausea and cracking or drying of skin. Avoid contact with skin. Avoid breathing mist or vapor. Wear safety glasses, protective clothing and chemical resistant rubber gloves when handling. Wash thoroughly after handling. Avoid swallowing.

Pressed wood products are sheet materials in which wood is largely in the form of strips, veneers, chips, strands or fibres. The wood particles are bound together by glue which is commonly a formaldehyde based resin. Pressed wood products include: plywood used for panelling, furniture and other products.

https://www.nicnas.gov.au/chemical…name/formaldehyde-in-pressed-wood-products

list of solvents – commercial products here. very useful for vanish and paint ingredients.