Method of casting

#This invention relates to a method of casting material and a mould therefor.

#A problem with existing methods of producing effects and textures on the surface of cast liquids, for example concrete, is that the resolution of the resulting product is generally not of a level sufficient for fine detail or complicated designs to be sufficiently clear. Whilst the concrete might be able to produce a good level of resolution, the mould in which the concrete is cast is of poor resolution. Furthermore, the depth of the resulting design on the concrete may be insufficient for the design to be visible from a distance.

#One method of casting concrete is to produce a mould from wood or other materials into which concrete is poured to produce a cast product.

#Once a design has been settled upon, it is processed using known techniques to generate a processed image optimised to produce a high resolution mould. During the processing, the image is converted into a pattern, which can be linework and dots of varying shapes and sizes so as to allow tone and halftones to be produced, thus producing a final image with degrees of ‘shading’ when viewed from a distance.

#One particular method of processing the image involves the steps of: Selecting a 2-dimensional colour image to be turned into a 3-dimensional relief pattern; Creating different surface textures and effects by varying the line widths, colours and opacities; Adjusting the input and output levels of the image histogram to alter the contrast and brightness levels of the image; Changing the image to a greyscale image; Inverting the image to produce a negative of the image; and Applying an appropriate halftone screen if the image contains tonework, for example, applying a halftone screen resolution of 120 lines per inch (2.54 centimeters).

#It may be preferable to adjust the output levels from the full scale to a reduced scale by cropping one or both of the extremities of the scale and recalibrating the scale thereafter. For example, the output levels may be cropped from 0-255 to 20-255, with the latter then constituting 100% of the scale. This can assist with improving the quality of the mould created from the photopolymer.