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1. (WO1992009929) DIFFUSION TRANSFER RECEIVER
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CLAIMS;

1. A diffusion transfer receiver comprising a support layer, a non-light sensitive image receiver layer coated onto each face of the support layer, said image receiving layer including catalytic nuclei for physical development of transferred complex silver halide, characterised in that the imaging
characteristics on each side of the support are different.

2. A receiver according to claim 1 characterised in that a receiver layer includes a diffusion modifying active component, said active component of a or each image receiving layer differs to provide a diffusion transfer receiving layer adapted for a different end use.

3. A receiver according to claim 1 or 2 characterised in that the diffusion modifying active component is a tone controlling compound which may differ for each layer thereby to provide different D-max transferred silver transmission densities over the spectrum for each image receiving layer.

4. A receiver according to claim 3 characterised in that the tone controlling compound(s) in a first layer is selected to have a relatively lower transmission density in the visual range and a relatively higher transmission density in the blue and UV range than the tone controlling compound(s) of the second layer.

5. A receiver according to any preceding claim characterised in that the support layer is a clear photographic base overlayed on each face by a three layer composite, each composite including an
underlayer comprising gelatin and a second tone controlling compound, a nuclei layer comprising nickel sulphide modified by addition of silver iodide and a first tone controlling compound, and a gelatin
supercoat layer.

6. A receiver according to claim 5 characterised in that the underlayer also includes a hardening agent and the supercoat includes a surfactant.

7. A receiver according to either of claims 5 or 6 wherein the first tone controlling compound in the underlayer in each layer is 2-phenyl-5-mercapto-oxadiazole, -and wherein the tone controlling compound of the nuclei layer is selected from 3-S-thiuronium propane sulphonate or
5-methylbenzotriazole.

8. A receiver according to any preceding claim wherein the sheet includes means indicative of the different characteristics of each face of the
receiver.

9. A receiver substantially as hereinbefore set forth with reference to and/or as illustrated in Figures 1 to 3 and or the foregoing Example.

10. A method for improving transmission density of a receiver sheet in a non-light-sensitive image
receiving layer of a silver diffusion tranfer process which method comprises utilizing in a receiver layer an S-thiuronium alkyl sulphonate.

11. A method according to claim 10 wherein the alkyl sulphonate is 3-S-thiuronium propane sulphonate.

12. A method according to either of claims 10 or 11 wherein the spectrophotometric absorption at 410 nm is in excess of 3.50 and wherein the absorption at 365 nm is in excess of 2.75.

13. A method according to claim 12 wherein the spectrophotometric absorption at 410 nm is in excess of 4.00 and wherein the absorption at 365 nm is in excess of 3.00.

14. A method according to any of claims 10 to 13 wherein the transmission density (DT) is about 3.50.