Retouching Medium

X. The mediums recommended in the regular retouching lessons have been found most suitable for all practical purposes, but should it be desired to experiment with other varnishes, any of the following will be found to give good results:

(a)

Alcohol..............................

5 ozs.

Gum Sandarac....................

1 oz.

Castor Oil............................

5 ozs.

Venice Turpentine...............

2 drs.

(b)

Turpentine............................

1 oz.

Powdered Resin....................

30 grs.

(c)

Alcohol...................................

1 oz.

Benzine...................................

2 ozs.

Acetone...................................

2 ozs.

Gum Sandarac.........................

1/2 oz.

(d)

Turpentine.................................

1 1/4 ozs.

Gum Damar.................................

75 grs.

Oil of Lavender..........................

25 drops.

Ruby Varnish

Dissolve 60 grains of finely powdered aurine in 20 ozs. of ordinary negative varnish, and apply to the glass in the usual way. Prepared ruby varnish is obtainable from any dealer in photographic supplies, and it is cheaper to purchase it already prepared rather than to attempt preparing the mixture oneself.

Removing Varnish

To remove varnish rub with a wad of cotton saturated with spirits of turpentine or alcohol.

Vaseline

The more or less purified residue from the distillation of petroleum. Light yellowish or semi-solid, having an ointment consistency. Soluble in ether, chloroform, benzine, and slightly soluble in alcohol; insoluble in water and glycerine. Use: Rubbed around a glass stopper will prevent it from sticking. Rubbed on top of a cork stopper will prevent the air from entering the bottle. Used for making paper transparent.

Vehicle

A substance usually of a viscous nature. Used to hold sensitive silver salts in suspension. The common vehicles used in photography are albumen, collodion, gelatin, etc.

Velox

A trade name applied to gaslight paper. Used by Eastman Kodak Co.