Liquid bandages.

I. Preface

This guide does not cover deep punctures, deep lacerations or deep burns. This is for small lacerations, abrasions, road rash, and minor injuries.
Do not apply liquid bandages over already infected injuries, those need drainage, not sealing.
This guide is for field use and people without easy access to a clean hospital.
Liquid bandages are not magic.

II. Equipment and brands

Solutio Novikov also known as Novikov's Solution is a commonly used liquid bandage in Eastern Europe, 10 grams cost ~2 dollars where i live.
It is a clear, dark green, viscous solution with a characteristic ether smell that leaves a dark green, well-adhering protective film on the skin after application and evaporation of the solvents. The tannin it contains has an astringent effect, while brilliant green has an antibacterial effect. The solution also has fungistatic and hemostatic effects. It is used for abrasions and minor injuries and for treating the skin around stitches.
New-Skin Liquid Bandage, LiquidSkin, Elaskin, Dermabond are all American replicas of Novikov's Solution, made from different chemicals. They are all waterproof but only the first one is antibacterial.
TraumaPet gel Ag is a German liquid bandage for animal use, it's similar to the American human counterparts.

III. Application

First, the injury must be cleaned of all foreign particulates, flush it with clean water or saline.
Under no circumstances should the liquid bandage come into contact with the eyes or mucous membranes of the mouth. It shouldn't be applied on wet injuries and it should be allowed to dry before coming into contact with water.
The area can be gently dried with sterile gauze.
When applying the liquid bandage, maintain thin layers, let each dry. Do not glob it on.
You shouldn't apply any dressings over the film, leave it open to the air unless the injury is in a precarious location that could worsen it with movement/friction.

IV. Post-application care and observation

Check the injury site every hour. Watch for heat, pus, or spreading redness, all signs of infection.
Liquid bandages wear off after ~5–7 days naturally, do not peel them off unless necessary.
In jungle/swamp/desert environments: reapply every 12 hours if exposed to moisture or friction.

V. My notes

It should burn heavily when being applied; this will stop once the solvents evaporate.
Try to get the bottles which have an applicator brush inside their caps, it is notoriously difficult to apply without them.
The applicator brush can be shared by multiple patients. The brilliant green from Solutio Novikov (provided it has not expired) has a bactericidal and fungistatic effect as mentioned above (i.e., it is not effective against viruses). Personally, I have not encountered a case of infection demonstrably acquired through contaminated disinfectant. However, I would not dare to claim that it is impossible. It would be a rarity, confirmed with certainty only by microbial analysis of the residual solution.
It stains like hell, if you get it on clothing, you are done and there's no saving it.

VI. Novikov specifications

Novikov, or more precisely Solutio Novikov, is the trade name for a mixed solution, containing 1% brilliant green, collodion, and ethanol. As mentioned before, it has bacteriostatic and fungistatic effects, i.e., it suppresses the growth of bacteria (effective against gram-positive bacteria) and fungi, which is very useful for open injuries.
I will break the composition down into the number of grams that need to be mixed: 0.913 g of brilliant green, 0.913 g of 96% ethanol, 91.325 g of collodion (4.566 g of tannin and 2.783 g of castor oil are also added). This will yield ~100.5 g of Solutio Novikov, not accounting for the evaporation of ethanol or ether in collodion.
According to the Antiseptic Prophylaxis and Therapy in Ocular Infections, even a 0.01% solution of brilliant green completely suppresses the occurrence of bacteria Staphylococcus aureus, Staphylococcus faecalis, and Escherichia coli. Aggressive staphylococci are a common cause of so-called surgical infections.
Collodion, the second component that makes up most of the liquid, ensures the formation of an impermeable coating, a "film". It is a solution of nitrated cellulose in a mixture of alcohol and ether. The addition of castor oil (see above) creates elastic collodion, which is used in medicine to cover injuries, excoriations, and burns, and to coat pills.