Ship Camouflage Instructions
United States Navy
Ships - 2
Bureau of Ships
January 1941

 

Chapter 1
Introduction

 

Scope of These Instructions.

The instructions  give specific and detailed measures for the painting of surface ships and submarines for the purpose of low visibility and deception.  In order to give a reader unfamiliar with the subject a clear understanding of developments up to the present time, there is included in Chapter 4 a brief but fairly complete survey of information resulting from experiments on which the measures are based. Other considerations on which additional information is desired are brought to attention.

Revision.

This booklet is assembled in loose leaf form with the object of facilitating revision as further information becomes available.  It is requested that pertinent comments be submitted via the chain of command and that instances of notably effective or ineffective camouflage be noted with particular care taken to evaluate all the circumstances.

Definition of Ship Camouflage.

Ship camouflage means painting a ship for the purpose of producing effects of low visibility and of deception in course and range estimation.

Camouflage Colors.

Four colors are employed in camouflage painting; these are three shades of gray, also black.  the three gray colors are called "Dark Gray", "Ocean Gray", and "Light Gray" designated by formula numbers 5-D, 5-O, and 5-L respectively. The "Light Gray" color is the same as that designated in Appendix 6, "Instructions for Painting and Cementing Vessels of the U.S. Navy," Edition 1939 as formula #5 "Standard Navy Gray." The black color is the same as designated by formula 82, in this publication.  The four colors are shown in Plate 1.  The percentage diffuse reflectance of each color for white lights is also given in Plate 1. This is the standard method  of specifying the brightness or darkness of a gray color.  The gloss value or shininess is also given.
The colors of Plate 1 MUST NOT be used as standards from which to mix paint.

Light Reflection.

Lightness in color means the ability of a surface to reflect light DIFUSELY.  It is usually thought of as varying in degree from white through gray down to black.  It is commonly expressed in percentage reflection where the standard surface, reflecting 100%, is a surface of pure magnesium oxide.

A low reflectance is considered the characteristic most to be desired in camouflage paints for low visibility, and the paints which have been developed have had other qualities sacrificed as necessary in order to obtain this feature.

Gloss.

Gloss is the ability of a surface to reflect light SPECULARLY which means regularly or like a mirror.  Qualitatively the results are reported as glossy or mat.  Five types of gloss are recognized, but for this discussion only two are important.  OBJECTIVE gloss is reported in terms of an arbitrary scale by which the amount of light reflected specularly from the surface in question is compared to the amount reflected specularly from a standard gloss surface of polished black glass.  Six percent reflection is called 60, 4% called 40, etc.  COMPARATIVE gloss is a ratio between the amount reflected in the mirror direction and that reflected in another specific direction ( usually normal ) .  It is a measure of the amount of so-called high lights a rounded surface will show.

A low gloss is desirable in camouflage paints to avoid distinct reflections from flat or curved surfaces in sun or searchlight beams.  It is distinctly a difference characteristic from reflectance and is relatively less important.

To distinguish between reflectance and gloss, compare a shiny new white refrigerator and a shiny new black automobile.  Both may have the same objective gloss value (about 60), but the reflectance of the white refrigerator would be 88% whereas the reflectance of the automobile would only be 4%.

The old Navy Standard light gray paint formula #5 had a gloss value of  44 which weathers down to about 28 after 30 days exposure.  The reflectance of this color is about 44%.  A marked reduction in gloss has been obtained in the new formulas as noted in Plate 1, and due to the darker color of formula 5-D, reflectance is much less.

Table of Contents ] Next Page ]