CN115598915A - Combined printing process of blue-drying and gum dichromate - Google Patents

Abstract

The invention discloses a photo developing method. The method first makes the photo into middle negative according to CMYK four colors, uses bichromate as photosensitizer, matches with Arabic gum and watercolor as fuchsin and yellow source, and can determine whether to print black according to the color of the original. And then ferric ammonium citrate is used as a photosensitizer to make potassium ferricyanide appear dark blue on paper, and finally, the picture product with various colors is prepared. The method provided by the invention can be used for manufacturing paper pictures with different colors and unique characteristics, has strong designability of patterns, and is more environment-friendly than the original gum dichromate process.

Description

Combined printing process of blue-drying and gum dichromate

Technical Field

The invention belongs to the technical field of photo artware, and particularly relates to a photo developing method.

Background

Blue-and-white photographic technology is a classic photographic technology, and its imaging principle is that the photographic paper coated with photographic agent and covered with negative film is exposed and developed by utilizing ultraviolet ray to produce blue-and-white image. In recent years, people continuously develop a 'blue drying' technology, widen the application field of 'blue drying', gradually develop the technology into the technology of not only exposing on paper, but also exposing on fabrics, and can be applied to both the production of prints and the design of cultural originality. The gum dichromate process is a color one hundred year process printing process which is extremely easy to operate and is rich in creativity. The process is the oldest and earliest color photo printing process in the world, has simple principle and economical materials, and the used watercolor can be beautiful as it is after hundreds of years under the condition of proper storage.

However, blue sun mainly consists of blue and white, the color is slightly single, the spirit requirement and aesthetic requirement of people cannot be well met, and for some existing improvements of the blue sun, such as later hand painting and coloring, the blue sun contains less knowledge and has the same defects of complicated steps and complex process as the method of using the gum dichromate by light. If the Chinese character is used in the popular text creation, the effect is not good.

Disclosure of Invention

In order to solve the defect of monotonous color of the traditional blue-light process developed photo in the prior art, the invention provides a novel photo developing method combining blue-light and gum dichromate process.

In order to solve the technical problems, the invention adopts the following technical scheme.

(1) The photos to be printed are processed on a computer to be made into films respectively.

(2) The photographic paper to be developed is processed in the early stage.

(3) And (3) preparing a photosensitive liquid medicine by a gum dichromate method, and carrying out developing printing on channels except a cyan channel.

(4) The photopapers that had been developed by the gum dichromate process were coated again with gum arabic.

(5) Preparing a blue-light liquid medicine, and carrying out cyan printing.

(6) After development, the picture products with various colors can be obtained.

In the above-mentioned scheme, (5) the original cyan printing is replaced by the blue-sunning, so that the black channel printing is not required for the photos with lighter overall color tone or less black parts.

In the scheme, the photographic paper should be fine grain water color paper containing cotton fiber.

In the above scheme, the process (1) includes three steps of channel separation, black and white, and inversion according to CMYK colors, and cross marks for alignment should be added at the corners of the film. And then printed onto the corresponding film using a suitable printer to produce a printed intermediate film.

In the scheme, the preliminary treatment of (2) refers to shrink-proof treatment of the paper, and specifically comprises two steps of soaking in clear water and naturally air-drying.

In the above scheme, the gum dichromate method of (3) comprises six steps of gum arabic coating, air drying, photosensitive solution coating, air drying, exposure and development.

In the above embodiment, the photosensitive chemical liquid component in (3) is (taking ammonium dichromate as an example) gum arabic, 200g/L ammonium dichromate solution, and watercolor pigment corresponding to the color.

In the scheme, the development in the step (3) is soaked in clear water, and the water is used for soaking until the pigment of the non-photosensitive part is completely washed away, so that a soft brush can be used for assisting in cleaning.

In the above protocol, it should be ensured that the spread of gum in (4) is sufficiently uniform.

In the scheme, the printing component photosensitive liquid medicine of the step (5) is coated, air-dried, exposed and developed, and the pigment Prussian blue Fe3 [ Fe (CN) 6 ]2 with excellent performance can be formed through the process.

In the scheme, the components of the blue-sunning liquid medicine in the step (5) are 180-200g/L ferric ammonium citrate solution and 80-100g/L potassium ferricyanide solution.

In the above embodiment, the developer (6) contains 0.1 to 0.2g/L of hydrogen peroxide solution.

In the above schemes, exposure refers to exposure under sunlight containing wavelength 238-435nm or ultraviolet light of 238-400nm, wherein the gum dichromate method exposure time is 480s-960s, and the blue sun exposure time is 960s-1800s according to the intensity of light.

In the scheme, the coating and air drying of the photosensitive liquid medicine are finished in a dark place.

The invention provides a novel photo developing method, which adopts a brand-new exposure and development process and a photosensitive paper manufacturing process to finally prepare picture products with various colors. The method provided by the invention adopts a brand-new color photo developing process, combines the blue drying process and the gum dichromate process, and can automatically change the color of watercolor pigment in the gum dichromate process to manufacture paper pictures with different colors and unique features. The colors of the traditional blue tanning are enriched; compared with the traditional gum dichromate process, the process has the advantages of simple and feasible steps and strong designability of patterns, has higher science popularization and commercial value, realizes safety and simplicity, and is suitable for science popularization display and artware manufacturing.

Drawings

FIG. 1 is a process flow diagram of a photo processing method according to the present invention.

FIG. 2 is a color picture produced by the photo printing method of example 1 according to the present invention.

FIG. 3 is a color photograph produced by the photo-printing method of example 2 according to the present invention.

FIG. 4 is a graph of exposure time versus intensity of a light source

Detailed Description

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments. Fig. 2 and 3 are not colored, and are only represented in black and white.

Example 1.

1) The photo to be printed is separated according to four channels of CMYK on a computer, black and white and reverse processing are carried out, a cross pattern is added at the corner, and then the photo is respectively printed on the film by using a proper printer.

2) Soaking 16K fine-grain watercolor paper containing 50% of cotton fiber in normal temperature water for 2min, and naturally air drying in a ventilated place.

3) The shrink-resistant treated paper was evenly smeared with approximately 6ml of gum arabic solution using a soft brush (gum to water ratio 1: 2) And naturally air-drying.

4) A black photosensitive agent is prepared, and the formula comprises 6ml of Arabic gum solution, 6ml of 200g/L ammonium dichromate solution and 0.5g of No. 708 watercolor pigment.

5) And (3) uniformly coating a black photosensitive medicament by using a soft brush, and naturally drying.

6) The black channel film is tightly attached to photographic paper and exposed for 10min in the sun at noon in summer.

7) And shaking and developing the exposed photographic paper in clear water for 2min, and naturally drying.

8) The magenta and yellow pigments were exposed according to the procedures (3) to (7) above, and the watercolor pigments were No. 370, no. 0.4g and No. 268, no. 0.6g, respectively. The exposure time of magenta is 10min, and the exposure time of yellow is 12min.

9) The gum arabic solution application was performed again, and air-dried naturally.

10 200g/L brown ferric ammonium citrate solution and 100g/L potassium ferricyanide solution were prepared in a 1:1 mixed, coated and air dried.

11 The cyan channel film was tightly attached to the photographic paper and exposed to the sun at noon in summer for 16min.

12 Exposed photographic paper was shaken and developed for 1min on each side in 0.1g/L hydrogen peroxide solution, and air-dried naturally. And obtaining the picture products with various colors.

Example 2 (for photographs with lighter overall hue or fewer black areas).

1) Separating the picture to be printed according to four channels of CMYK on a computer, abandoning a black channel, carrying out black-white and reverse processing on the other three channels, adding a cross pattern at the corner, and then respectively printing the picture on a film by using a proper printer.

2) Soaking 16K fine-grain water-color paper containing 50% of cotton fibers in normal-temperature water for 2min, and naturally drying in the air.

3) The shrinkproof treated paper was evenly smeared with about 6ml of gum arabic solution using a soft brush (gum to water ratio 1: 2) And naturally air-drying.

4) A magenta photosensitive agent is prepared, wherein the formula comprises 6ml of Arabic gum solution, 6ml of 200g/L ammonium dichromate solution and 0.4g of No. 370 watercolor pigment.

5) Uniformly coating magenta photosensitive agent with a soft brush, and naturally drying.

6) The black channel film was tightly attached to photographic paper and exposed to the sun at noon in summer for 10min.

7) And shaking and developing the exposed photographic paper in clear water for 2min, and naturally drying.

8) Yellow color was exposed to light according to the procedures (3) to (7) above, and the watercolor pigment was No. 268.6 g. Exposure time was 12min.

9) The gum arabic solution application was performed again, and air-dried naturally.

10 200g/L brown ferric ammonium citrate solution and 100g/L potassium ferricyanide solution were prepared in a 1:1 mixed, coated and air dried.

11 The cyan channel film was closely attached to the photographic paper and exposed to the sun at noon in summer for 20min.

12 Exposed photographic paper was shaken and developed for 1min on each side in 0.1g/L hydrogen peroxide solution and air-dried naturally. And obtaining the picture products with various colors.

Example 3 selection of exposure time.

Because the handicraft adopts two printing methods at the same time, the handicraft has certain requirements on the exposure time, and experiments show that the optimal exposure time and the light source intensity are shown in figure 4.

Furthermore, because the handicraft belongs to one of the artwork, the exposure time can be properly increased or decreased, and the artworks with rich colors and different styles can be obtained.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be construed as the protection scope of the present invention.

Claims (4)

1. A method for developing a photo, said method comprising dividing the photo into four color channels of CMYK, developing three colors of black, magenta and yellow by the gum dichromate method, and developing cyan by the blue-printing method.

2. A photo printing method is characterized in that the used photographic paper is fine grain water color paper containing 50% of cotton fiber.

3. A photo printing method is characterized by comprising the following steps:

(1) Processing the photos to be printed on a computer to respectively prepare films;

(2) Performing early-stage treatment on photographic paper to be developed;

(3) Preparing a photosensitive liquid medicine by a gum dichromate method, and carrying out developing of other channels except a cyan channel;

(4) Coating the photographic paper which is processed by the gum dichromate method with Arabic gum again;

(5) Preparing a blue-drying liquid medicine, and carrying out cyan printing;

(6) And (5) developing.

4. A method of processing photographs as claimed in claim 3 wherein the processing of the black channel in step (3) is replaced by blue tanning in photographs of lighter shade and less black.

Images