DE807895C - Process for making halftone gold prints on ceramic material - Google Patents

Description

Process for making halftone gold prints on ceramic Material plan take a drawing paper provided with a grid and draw with black Chalk pen the image you want for gold printing on this paper. The drawing has to go under slight pressure of the pen, because only the top tips of the grid may be touched in order not to be blatant in effect. on this titmouse will break down the picture into points and thus form the basis for any Tonal values created for gold printing. This type of gold printing is used in the china industry not yet available and therefore even a need.

Now the photomechanical work begins by drawing from the drawing a negative and from it a slide is made, but always pays attention to sharpness.

Now take a piece of red pigment paper and place it in a bath (4o 9 potassium dichromate dissolved in 1 liter of water) to make it light-sensitive. This is done by placing the pigment paper in the bath with the layer side down until the edges of the paper start to bend upwards. Now it is taken out, squeezed onto a previously cleanly cleaned glass plate with the layer side down using a squeezer and brought to dry in a dark room. Before proceeding with the copying process, the drawing of the slide is pasted with a strip of opaque paper, placed in the copier frame with the layer side up, the pigment paper, which has meanwhile been dried, is placed with the layer on the positive and brought to the light in the frame under strong pressure. The time of copying cannot be specified precisely as it depends on the depth of the drawing and the light itself, but it can usually take 15 to 25 minutes. However, personal practice or experience allows the time to be kept fairly precisely.

A copper plate, clean grease-free with spirit and chalk made, is in a bowl under water. ser laid. The copied pigment paper is now cut to just about the non-copied strip on the copper plate put in the water and then soaked up wet.

For development, you then put it in hot water, whereby the Pigment paper can be peeled off the copper plate and only the exposed gelatin remains on it. Now you start the development by rinsing with hot water. The now clearly visible negative on the copper plate shows the termination the development. After the plate has dried, which takes about 1 /, day, everything that must not be etched is covered with asphalt varnish, including the back of the Copper plate.

The etching is now started. Four different mixtures of ferric chloride are provided in four enamel bowls. The mixture is calculated according to the degree of construction, namely 40, 38, 35 and 31 degrees. The acid must be warm to the touch. The printing plate is now etched in the first solution, the thinnest gelatin layer, i.e. the most transparent, being attacked first; when this is done, the copper plate travels through all subsequent solutions until even the most delicate point has been etched. Now the printing plate is washed off and cleaned with turpentine. It is now ready for printing.

To give the soft copper plate better printing durability, they are provided with a galvanic steel coating.

The plate is warmed up a little and used to make prints the printing silk paper that is customary for porcelain printing is used, from which prints are then made can be made on the ceramic material.

Claims (1)

PATENT CLAIM: Process for the production of halftone gold prints on ceramic material, characterized in that the original drawing is produced with chalk pen on grain paper, first a negative, then a positive made from it, copied onto pigment paper and transferred to a copper plate with the help of the same is etched and thus halftone gold prints are made on the usual printed silk paper, which are then transferred to the ceramic material.