GB2330795A

GB2330795A - Facilitation of the choice of paint according to the visual appearance of a dried coat when on a surface

Info

Publication number: GB2330795A
Application number: GB9723331A
Authority: GB
Inventors: Michael James Smith; Lezlie Hill; Ian Mark Kenyon
Original assignee: GRAND PREMIER Ltd; Imperial Chemical Industries Ltd
Current assignee: GRAND PREMIER Ltd; Imperial Chemical Industries Ltd
Priority date: 1997-11-04
Filing date: 1997-11-04
Publication date: 1999-05-05
Anticipated expiration: 2017-11-04
Also published as: DE29819417U1; GB9723331D0; EP1028855A1; GB2330795B; AU9549098A; WO1999022945A1

Abstract

The choice of a paint according to the visual appearance of a dried test coat (14) of the paint on a surface to be painted employs a dried test coat which forms part of a combination (11) which also comprises a supporting web (10) releasably bonded to one face (15) of the dried coat (optionally by means of a release adhesive 12) and an attachment layer 16 provided on the other face of the dried coat, the film being sufficiently thin and flexible to be conformable closely with a test area of the surface to be painted and wherein the combination is pressed against the test area so that its attachment layer contacts the surface sufficiently closely to hold the dried test coat on the surface and then the supporting layer is separated from the held fried test coat to expose the test coat whereupon the visual appearance of the test coat can be assessed after which the test coat together with its attachment layer can be peeled from the surface.

Description

2330795 FACILITATION OF THE CHOICE OF PAINT ACCORDING TO THE VISUAL

APPEARANCE OF A DRIED COAT YMEN ON A SURFACE R This invention relates to a method for facilitating the choice of paint according to the visual appearance of a dried coat of the paint when in position on a surface to be painted such as a wall or ceiling. The invention also relates to a transportable combination including a dried test coat of paint for use in the method and a transportable assembly of a plurality of such combinations.

Before painting a wall or ceiling or other surface such as door, doorframe, window frame or 10 radiator which forms part of a building, it is of course necessary to choose the shade of colour and the sheen of paint required. The "sheen" of a paint is a measure of the reflectance of a dried coat of the paint and typical sheens include "gloss", "silk", "eggshelP and "matt". Up till now, such choices have been made by a customer looking at small areas of colour and sheen reproduced on a printed so-called "colour charC and in the case of a limited range of paints, it has been possible to further facilitate their choice by the provision of small test quantities of paint in so-called "tester" pots so that a small test area of the surface can be test-painted.

2 Two problems arise when paint is selected using the printed colour charts. Firstly the shades and sheen are reproduced in ink which never quite faithfully reproduces the precise shade and sheen of a paint and the human eye is extremely adept at noticing differences in shade and sheen. Secondly, only a small area of shade or sheen is reproduced and many customers, especially amateur or Mo-it-yourself' customers, have difficulty in visualising the shade or sheen when in position on a large area of a wall or ceiling. A partial solution to these problems is obtained if the choice of shade and sheen is further facilitated by the use of test quantities of paint provided in "tester" pots. However the use of tester pots has its difficulties too. For example these days over 1600 different shades of colour are available in paints and the paints are usually available in three or four alternative sheens. Even though the tester pots are small in volume, it is not possible to stock pots for every combination of shade and sheen in a typical retail shop or trade store. In addition, the small size of the tester pots means that the test quantity of paint has to be applied to the surface using a miniature brush which makes the application of a uniform coating difficult (especially for amateurs) particularly when the dried coating is to be over 30gm (micrometers) thick. Such a minimum thickness is needed to ensure hiding of marks on the surface even when a paint of high opacity is used.

A further problem with tester pots is that the paint must be allowed to dry fully in order to obtain a faithful reproduction of the shade and sheen of the dried coat of paint. The need to wait for complete drying tests the patience of amateurs. Yet another problem arises from the fact that the dried coat of test paint remains on the surface and so it has to be covered and obscured by the dried coat of the ultimately chosen paint. The dried test coat may sometimes be discernible as a small area standing proud in the final dried coat or as an area of slightly different colour shade caused by a failure to obscure the test coat fully.

3 An object of this invention is to provide a method for facilitating the choice of a paint according to the visual appearance of a dried coat of the paint when in position on a surface to be painted which method gives an almost instant and faithful reproduction of the shade of colour and sheen of the dried coat when on the surface and which does not detract from the appearance of a subsequently applied dried coat of paint. Another object is to provide a transportable combination including a dried test coat of paint for use in the method and a transportable assembly of a plurality of such combinations.

Accordingly this invention provides a method for facilitating the choice of a paint according to the visual appearance of a dried test coat of the paint on a surface to be painted wherein the method includes the steps of (1) providing the dried test coat of paint as part of a transportable combination (11) which also includes (a) an attachment layer (16) provided on one face (13) of the dried test coat and which layer is sufficiently thin and flexible to be conformable closely with the surface to be painted and (b) a supporting web (10) releasably bonded to the other face (15) of the dried test coat, (2) optionally moistening a test area of the surface with water and then pressing the combination against a test area of the surface so that its attachment layer contacts the surface and conforms sufficiently closely to hold the dried test coat on the surface, (3) separating the supporting web from the held dried test coat so as to expose the face of the test coat to which the web was bonded, (4) assessing the visual appearance of the dried test coat and (5) peeling the assessed dried test coat together with its attaching layer from the surface.

4 Both the dried test coat and the attachment layer can be formed under closely controllable factory conditions so ensuring a highly uniform coat and layer and also thorough drying of the paint all of which leads to a very faithful reproduction of shade and sheen. Removal of the test coat after assessment means that it will not interfere with any subsequently applied coat 5 of paint.

The dried test coat of paint has a thickness which is preferably in the range of 30 to 150tin (especially 35 to 10Ogrn) to ensure good obliteration of the marks, scores and dents often found on or in walls and ceilings. It is preferred that the dried paint should have a very high opacity which can be expressed as a "Contrast RatiJ of at least 90% and preferably over 98% when determined according to the method described later. Most paints including the test paints contain rutile titanium dioxide to confer opacity but in order to ensure good wear resistance, it is preferred that the concentration of rutile should not exceed about 50wt% of the dried coat and usually the rutile is present in a range of from 5 to 38wt% of the dried coat.

It is also preferred that the rutile particles should have a low sheen or reflectance and in particular their reflectance should be low in order to avoid localised excessive shine in a wall or ceiling paint. The volume solids content of the liquid paint is preferably from 25 to 60%, which is to say that 25 to 60 volume % of the liquid paint is non-volatile material such as rutile, other pigments, extenders and film-forming resin as discussed below.

In addition to rutile, paints suitable for use in this invention will often contain pigments imparting other colours. These pigments (insoluble colorants), which are commonly used in the paint industry, are distinguished from dyestuffs (soluble colorants) which are commonly used in the printing industry and which are relatively expensive. The efficiency of the rutile and the pigments will generally be promoted by the presence of so-called extenders which space apart the pigment particles. Extenders include china clay (kaolin), chalk, powdered limestone and talc.

The dried test coat of paint may be obtained from an aqueous emulsion paint (sometimes called "latex paint") such as a vinyl or acrylic emulsion paint or from an aqueous or organic solvent-based alkyd paint. The vinyl, acrylic or alkyd resins serve as the film-forming binders which hold the components of the dried coat of paint together. More specifically, the paint is preferably selected from those containing aqueous emulsions of acrylic or vinyl copolymers or organic solvent-borne alkyd resins all having weight average molecular weights of over 200,000 and viscosities of from 0.3 to 1.2 (preferably 0.4 to 0.8) pascal second (Pa.s) when measured at 25'C using an electrically operated "Rotothinner'according to the method of use for the "Electric Operated ModeF' as described in the leaflet "Sheen/ICI Rotothinners" available from Sheen Instruments Limited of Kingston-on-Thames, England.

Typical examples of acrylic copolymers are the copolymers of usually two or more alkyl unsaturated carboxylates, especially C, to Cs alkyl acrylates and/or methacrylates and in particular the methyl, ethyl, butyl and 2-ethylhexyl esters. These alkyl esters are ftequently copolymenized with acrylic or methacrylic acids to provide groups convertible to salts to confer water- solubility or hydrophilic characteristics. Preferred acrylic copolymers have weight average molecular weights of from 500,000 to at least 1,000,000 and above where meaningful determination of molecular weights becomes difficult and ceases to be worthwhile.

Typical examples of vinyl copolymers are the copolymers of vinyl carboxylates of which vinyl acetate and vinyl esters of Cio to G, acids are the most important. Hydrophilic character is often imparted to the polymers by hydrolysing a portion of the acetate or other 6 carboxylate moieties to forni hydroxyl moieties, i.e. notional copolymerized vinyl alcohol.

The weight average molecular weight of vinyl polymers and copolymers is preferably from 100,000 to 1,000,000.

Alkyd resins are formed by the partial condensation of polyols such as glycerol or pentaerythritol with dicarboxylic acids or anhydrides such as isophthalic anhydride and terephthalic acid, and then condensation of unreacted hydroxyl groups with long chain (C, to C30) unsaturated fatty acids such as oleic, ricinoleic, linoleic, linolenic and licanic, all derivable from natural oils. The minimum weight average molecular weight of useful alkyd resins is usually 100,000 and preferably 200,000. However, the possibilities for cross-linking mean that their molecular weights may be very much higher and often in the region where molecular weight determinations become meaningless.

The attachment layer may be any layer which is sufficiently thin and flexible to be conformable closely with the surface to be painted when pressed against the area and which more particularly conforms closely enough to the contours of the surface to cling to it well enough to hold the dried test coat against the surface. Clinging may be assisted if the surface is first moistened with water. The layer should preferably have a thickness of no more than 1 to 1Ogm and be formed from a film-forming thermoplastic resin having a glass transition temperature (Tg) of below O'C and preferably below -10'C to ensure good flexibility. Tg may be determined in accordance with the procedures disclosed in European Patent Specification

EP 0 425 085A, the contents of which are herein incorporated by reference. The layer may be lightly crosslinked to give it increased tensile strength.

Suitable film-forming thermoplastic resins for use in forming the attachment layer include polymers and copolymers of the alkyl acrylates, and methacrylates and of the vinyl 1 7 carboxylates and alcohols mentioned above. They also include plasticised polyvinyl chlorides and ethylene vinyl acetate copolymers of the types used in making the commercially available thin flexible films known as "cling" films.

The attachment layer clings to the surface to be painted probably by means of electrostatic attraction or possibly by means of some inherent tackiness of the sort associated with pressure sensitive adhesives and possibly by a combination of both. The attachment to the surface is therefore firm but easily interuptable to allow separation of the test coat and attachment layer from the surface. The thinness and conformability of the attachment layer means that the appearance of the dried test coat when on the surface very much resembles a dried coat of paint which has been applied conventionally using a brush or roller.

The supporting web may be any sheet material available either in short lengths or in a relatively continuous length taken from a roll. The web must be releasably bonded to the test coat in a way which allows easy separation of the web after the dried test coat has been positioned on the wall. Preferably the web is bonded to the coat by means of a layer of release adhesive. If the release adhesive is a transparent pressure sensitive adhesive, the supporting web may be a paper of the type used in making temporarily adhesive notepaper. However the preferred adhesive is a water- release adhesive and for use with these it is necessary to use a supporting web having a water-permeable capacity which in practice usually means a paper sheet. It is preferred to use a sheet of so-called "duplex" paper comprising a thin water-permeable tissue layer opposed to the adhesive and integral with the tissue layer is a less permeable (usually heavily calendared) paper layer. Suitable "duplex" paper may be obtained from Britains (TR) Limited of Stoke-on-Trent, England.

8 The water-release adhesive layer is preferably formed of dextrin or other water-soluble gum. Such water-release adhesive materials are activateable by moistening and are per se well know in the water-release decalcomania field.

The combination of dried test coat, attachment layer, release adhesive and supporting web 5 may be made by sequential coating of the adhesive, test coat and attachment layer onto the supporting web. For example an organic solvent borne solution of pressure sensitive adhesive or an aqueous water-release adhesive is first coated onto the web and positively dried (for example by warm (35 to 5WC) air) or allowed to dry until it becomes form-stable. Suitable coating techniques include roller, brush or spray coating, but roller-coating is preferred.

A wet coat of paint is then coated onto the form-stable adhesive to a thickness of preferably about 175 to 225% of the thickness required for the dried coat. Coating is preferably by means of roller or brush since these best reproduce the finish produced by the brush or roller of a decorator. However, spraying and silk-screen printing may also be used for greater convenience during the manufacturing process. When a silk- screen process is used with a water-based paint (e.g. an acrylic or vinyl paint) the paint should preferably contain a retarder, e.g. from 1 to lOwt% of drying retarder, typically a high boiling (boiling point preferably above 150'C) drying retarder liquid. Preferred retarders are alcohols, ethers, or carboxylates such as ethylene glycol, propylene glycol, poly (ethylene glycols) or poly (propylene glycols) of number average molecular weight 250 to 5,000 and preferably 250 to 500, methoxy propanol, di-isobutyl adipate and trimethyl pentanediol isobutyrate. Toxicity considerations lead to a preference for propylene glycol (usually used in amounts of from 4 to 7wt%) and poly (ethylene glycols) usually used in amounts of from 1 to 4wM 9 Finally the attachment layer is applied to the coat of paint when form stable. The layer may be applied by any of the coating techniques used to apply the adhesive or the coat of paint.

However it is also possible to apply the layer by hot melt coating or by pressing a thin pre-formed film of for example plasticised polyvinyl chloride or ethylene vinyl acetate copolymer against the coat of paint and also preferably whilst a dried coat of paint is still tacky. Pressure is conveniently applied by roller.

The combination obtained above may be obtained by coating supporting webs which are already of the required shape and size for providing a suitable sample area of dried paint or they may be cut from a relatively continuous web to provide such a sample area. A plurality of sample areas each comprising a dried coat of paint having a particular shade of colour or sheen may be bound together to provide an assembly of the combinations of dried test coats which offers the customer several alternative choices in a convenient package.

The positioning of the dried test coat on the surface is done by offering the attachment layer to a test area of the surface and firmly pressing and preferably also smoothing the combination onto the surface. Smoothing is intended to expel any air trapped beneath the combination. After pressing and smoothing, the combination holds firmly to the surface so that the supporting web can be removed. Where the release adhesive is a transparent pressure sensitive adhesive, removal is done by simply peeling the supporting web ftom the combination. Where the adhesive is a water-release adhesive, the supporting web is a simple sheet of water-permeable paper, the paper is first moistened with water whereupon water permeates through the paper and into the adhesive causing it to become releasable. The backing layer is then removed by peeling from the combination and any residual adhesive not removed with the paper is removed by gentle wiping with a damp sponge so as to expose fully the dried test coat. Where a duplex paper has been used, the less-permeable layer is first peeled away by rupture of the tissue layer. The residue of the tissue layer on the water-release adhesive is then moistened with water which permeates through the tissues into the adhesive causing it to become releasable. Again residual paper and adhesive can be removed by gentle g so leaving the dried test coat exposed. Any moisture left on the test coat is quickly sponginC, lost by evaporation so as to permit an assessment of the visual appearance of the dried test coat without the need to wait for more than a short period of time.

After assessment of the visual appearance, the combination of dried test coat and attachment layer is easily removed from the surface by peeling.

t The "Contrast RatiJ of a paint may be determined as follows:

In order to determine "Contrast Ratio% a sample of the paint under test is first filtered through an 80pm nylon mesh and then stood under vacuum to remove any air bubbles. Wet coats of the paint are then applied in turn to a standard white tile and to a standard black tile using a 1 00jum block spreader which applies a nominal 1 00jurn thick wet coat. The wet coats are allowed to dry at room temperature (about 18'C) for 24 hours to produce dried coats of the same thickness which is usually from 40 to 5Ogm. The light reflected from each coated tile is measured and the amount reflected from the black tile is expressed as a percentage of that reflected from the white tile. The measurements are repeated a further three times and the average percentage obtained from the four determinations is quoted as the "Contrast RatiJ.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a side view of an embodiment of a transportable combination of a dried test coat of paint, an attachment layer, a layer of release adhesive and a supporting web according to the present invention, and 11 Fig. 2 is a plan view from above of the combination shown in Figure Referring now to drawings, the combination 11 comprises a duplex paper supporting web 10 having a tissue layer 10a defining a water-permeable layer which is separable by rupturing from a less permeable layer 10b. Disposed on tissue layer 10a of paper web 10 is a water-release adhesive layer 12 formed of a dextrin-based water soluble gum. One face 15 of a dried test coat 14 of a water-based vinyl emulsion paint whose visual appearance is to be assessed, is bonded by adhesive layer 12 to paper web 10. Finally an attachment layer 16 is provided on the other face 13 of test coat 14. In this embodiment, the attachment film 16 is 2im thick and is formed of an acrylic resin of Tg below O'C.

The above combination 11 provides a sample area 18 (see Figure 2) of which has been cut to correspond to the shape of a typical test area of paint applied by brushing or rolling. Such a shape can be produced by cutting from a continuous web of the paper substrate 10 on which the layers 12, 14 and 16 have been coated in sequence.

It is envisaged that a wide variety of transportable combinations corresponding to the variety of shades and sheens of available paints will be provided at a retail or trade outlet for selection by the customer. A chosen combination can be applied to a test area of a surface (wall or ceiling) to be painted by moistening the test area with a damp sponge and then pressing the combination against the moistened surface with the attachment layer in contact with the surface, followed by smoothing where necessary to remove any air bubbles. The thinness and flexibility of the film 16 are such that it intimately contacts and clings to the surface of the surface sufficiently to hold and the dried test coat in position on the wall. Once in position, the less permeable layer 10b of the paper substrate can be peeled by rupturing in the plane of the tissue layer 10a. Any residual tissue layer 10a together with residual 1 12 water-release adhesive layer 12 can then be removed by gently moistening and wiping the surface layer 1 Oa with a damp sponge. Any residual moisture quickly evaporates leaving the paint layer 14 exposed for assessment purposes.

After assessment, the paint layer 14 and cover layer 16 can be removed from the surface by simply peeling so as to leave the surface with no remnants of the combination which would interfere with subsequent painting.

13

Claims

CLAIMS 1. A method of facilitating the choice of a paint according to the

visual appearance of a dried test coat (14) of the paint on a surface to be painted wherein the method includes the steps of (1) providing the dried test coat of paint as part of a transportable combination (11) 5 which also includes (a) an attachment layer (16) provided on one face (13) of the dried test coat and which layer is sufficiently thin and flexible to be conformable closely with the surface to be painted, and (b) a supporting web (10) releasably bonded to the other face (15) of the dried test coat.

(2) pressing the combination against a test area of the surface so that its attachment layer contacts the surface and conforms sufficiently closely to hold the dried test coat on the surface, (3) separating the supporting web from the held dried test coat so as to expose the face of the test coat to which the web was bonded, (4) assessing the visual appearance of the dried test coat and (5) peeling the assessed dried test coat together with its attachment layer from the surface.

2. A method according to Claim 1 wherein the test area of the surface is moistened with water 20 before the combination is pressed against it.

A method according to Claim 1 or Claim 2 wherein the supporting web is bonded to the test coat by a layer (12) of a release adhesive.

14 4. A method according to any one of the preceding Claims wherein the release adhesive is a water-release adhesive.

5. A method according to any one of the preceding Claims wherein the supporting web is a duplex paper which includes a layer (1 Oa) of waterpermeable tissue carried on a layer (1 Ob) 5 of less permeable paper.

6. A method according to Claim 5 wherein the water-permeable tissue is moistened with water when in position on the surface whereafter the adhesive becomes releasable.

7. A method according to any one of the preceding Claims wherein the attachment layer has a thickness of from 1 to 1 Oim.

8. A method according to any one of the preceding Claims wherein the attachment layer is a film of a resin chosen from the group consisting of polymers and copolymers of alkyl acrylates, alkyl methacrylates, vinyl carboxylates, vinyl alcohol, plasticised polyvinyl chloride and ethylene vinyl acetate copolymers.

9. A method according to any one the preceding Claims wherein the dried test coat of paint 15 has a thickness of at least 35im.

10. A method according to any one of the preceding Claims wherein the dried test coat has an opacity factor of at least 90%.

11. A transportable combination (11) for use in a method for facilitating the choice of paint on a test surface as claimed in any one of the preceding Claims wherein the combination includes (a) a dried test coat of paint (14), (b) a supporting web (10) releasably bonded to the test coat, (c) an attachment layer (16) provided on the dried test coat for attaching the combination to a surface to be painted which film is sufficiently thin and flexible to conform to the test surface.

12. A transportable as claimed in Claim 11 wherein the supporting web is bonded to a face 10 (15) of the dried test Elm by means of a layer (12) of a release adhesive.

13. A transportable combination wherein the adhesive is a water-release adhesive.

14. A transportable combination according to Claim 13 wherein the supporting web is a duplex paper which includes a layer (10a) of waterpermeable tissue carried on a layer (10b) of less permeable paper.

1515. A transportable combination according to any one of Claims 11 to 14 wherein the attachment layer has a thickness of from 1 to 1 Ogm.

16. A transportable combination according to any one of Claims 11 to 15 wherein the attachment layer is a film of a resin chosen from the group consisting of polymers and copolymers of alkyl acrylates, alkyl methacrylates, vinyl carboxylates, vinyl alcohol, 20 plasticised polyvinyl chloride and ethylene vinyl acetate copolymers.

16 17. A transportable combination according to any one of Claims 11 to 16 wherein the dried test coat of paint has a thickness of at least 35mm.

18. A transportable combination according to any one of Claims 11 to 17 wherein the dried test coat has an opacity factor of a least 90%.

19. A transportable assembly of a plurality of combinations as claimed in any one of Claims 11 to 18 wherein each combination in the assembly includes a dried test coat of a paint having a shade of colour and/or a sheen which is different from that of any other dried test coat in the assembly.

C.' 1-7.

Amendments to the claims have been filed as follows 1 - A method of facilitating the choice of a paint according to the visual appearance of a dried test coat (14) of the paint on a surface to be painted wherein the method includes the steps of (1) providing the dried test coat of paint as part of a transportable combination (11) 5 which also includes (a) an attachment layer (16) provided on one face (13) of the dried test coat and which layer is sufficiently thin and flexible to be conformable closely with the surface to be painted, and (b) a supporting web (10) releasably bonded to the other face (15) of the dried test coat. (2) pressing the combination against a test area of the surface so that its attachment layer contacts the surface and conforms sufficiently closely to hold the dried test coat on the surface, (3) separating the supporting web from the held dried test coat so as to expose the face 15 of the test coat to which the web was bonded, (4) assessing the visual appearance of the dried test coat and (5) peeling the assessed dried test coat together with its attachment layer from the surface.

2. A method according to Claim 1 wherein the test area of the surface is moistened with water 20 before the combination is pressed against it.

3. A method according to Claim 1 or Claim 2 wherein the supporting web is bonded to the test coat by a layer (12) of a release adhesive.

i.9 4. A method according to Claim 3, wherein the release adhesive is a water- release adhesive.

5. A method according to any one of the preceding Claims, wherein the supporting web is a duplex paper which includes a layer (10a) of waterpermeable tissue carried on a layer (1 Ob) of less permeable paper.

6. A method according to Claim 5 when appended to Claim 4, wherein the water-permeable tissue is moistened with water when in position on the surface whereafter the adhesive becomes releasable.

7. A method according to any one of the preceding Claims, wherein the attachment layer has a thickness of from 1 to 1 Opm.

8. A method according to any one of the preceding Claims, wherein the attachment layer is a film of a resin chosen from the group consisting of polymers and copolymers of alkyl acrylates, alkyl methacrylates, vinyl carboxylates, vinyl alcohol, plasticised polyvinyl chloride and ethylene vinyl acetate copolymers.

9. A method according to any one of the preceding Claims, wherein the dried test coat of paint has a thickness of at least 35gm.

10. A method according to any one of the preceding Claims, wherein the dried test coat has an opacity factor of at least 90%.

IC 11. A transportable combination (11) for use in a method for facilitating the choice of paint on a test surface as claimed in any one of the preceding Claims, wherein the combination includes (a) a dried test coat of paint (14), (b) an attachment layer (16) provided on one face of the dried test coat for attaching the combination to a surface to be painted, which layer is sufficiently thin and flexible to conform to the test surface, and (c) a supporting web (10) releasably bonded to the other face of the test coat, 12. A transportable as claimed in Claim 11, wherein the supporting web is bonded to a face (15) of the dried test film by means of a layer (12) of a release adhesive. - 13. A transportable combination as claimed in Claim 12, wherein the adhesive is a water-release adhesive.

14. A transportable combination according to Claim 13, wherein the supporting web is a duplex paper which includes a layer (1 Oa) of waterpermeable tissue carried on a layer (10b) of less permeable paper.

15. A transportable combination according to any one of Claims 11 to 14, wherein the attachment layer has a thickness of from 1 to 1Ogm.

16. A transportable combination according to any one of Claims 11 to 15, wherein the attachment layer is a film of a resin chosen from the group consisting of polymers and copolymers of alkyl acrylates, alkyl methacrylates, vinyl carboxylates, vinyl alcohol, plasticised polyvinyl chloride and ethylene vinyl acetate copolymers.

:250- 1 17. A transportable combination according to any one of Claims 11 to 16, wherein the dried test coat of paint has a thickness of at least 35gm.

18. A transportable combination according to any one of Claims 11 to 17. wherein the dried test coat has an opacity factor of at least 90%.

19. A transportable assembly of a plurality of combinations as claimed in any one of Claims 11 to 18, wherein each combination in the assembly includes a dried test coat of a paint having a shade of colour and/or a sheen which is different from that of any other dried test coat in the assembly.