Original selection and output of screen negatives
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
There are generally three types of commonly used originals for screen printing: black and white line pattern originals, color continuous tone originals, and color printed originals (secondary originals).
Q: How many line originals are there? Can hand-drawn drafts be replaced by computer drawings?
A: Black and white line pattern manuscripts generally have hand drawings and computer drawings. The hand-drawn drafts have a reflective manuscript and a transmissive manuscript, which are hand-drawn on white paper for the manuscript, and the text, graphics, tables, etc. drawn on the sulfuric acid paper in carbon black ink are transmitted. Density D = 3 or more, you can directly print the screen version.
Computer graphics are drawn by various software, such as documents, patterns, tables, etc., which are output on transparencies or sulfuric acid paper by laser printers as screen printing originals. In order to improve the printing quality, some factories currently use high-precision computer graphics.
Q: Why do I use color reversal film for screen printing originals?
A: Continuously coloring originals are:
1. The color reversal film is the most ideal transmissive original in screen printing. The image has high definition, bright colors, rich layers and strong stereoscopic effect, which is suitable for high magnification. The density range is D=0.1~3.8, and some can reach 4 or more. To scan the screen with a high-end scanner or an electric extension, the image quality can be guaranteed. Magnification can be enlarged by a factor of ten, suitable for large format screen printing, and is an ideal manuscript for large-scale advertising;
2. Color photos are printed with color negatives and can be used as reflective papers. However, there are some loss of image level in the printing (copying), or color imbalance, color cast and uneven color tone due to improper operation, the density range is D=0.1~2.6, the dye particles are rough, and the image is scanned by the platform scanner. Dirty magnification is 4~7 times, and then the image is magnified;
3. The color positive film is also copied through the color negative film. The image quality is the same as that of the color photo. It is a transmissive original with a density range of D=0.1~2.8. It is scanned by the platform scanner and placed at a magnification of 4~7 times.
Q: Why is color negative film not suitable for color separation?
A: This is because the color negative film has a layer of horse cover (amber) on the surface. It can't find the black and white field when scanning, which is not good for calibration. The screen does not see the effect, and it is not easy to master the color reproduction. The color of the image is the complementary color of the original scene, showing an inverse image. Generally, no original is used, and it can be copied into a positive film or a photo as a screen printing original.
Q: Why do printing originals go to the net? Why can't I enlarge the copy?
A: The printed manuscript, also known as the second manuscript, is mostly a mesh-reflected manuscript. It is a Y-, M, C, K four-color print that has been compressed. The density range is low, ranging from 0.1 to 1.6, and some reaching 1.8. rich. The density requirement for re-copying with a second original is the same, and it can only be copied in the original, and should not be enlarged, otherwise it will be seriously distorted. The density of the printed manuscript is lower than the density recognition ability of the scanner. It is scanned by the middle and low-end scanners to prevent the generation of moiré in the electric part copying. First, the netting is removed for blurring. If there is no netting function, the netting angle should be staggered. .
Q: When outputting the negative image of the dot, why do you want to use the laser image camera to produce the film?
A: Inkjet printers, laser printers, and laser imageetters can output transparencies for use as screen printing originals, but density and image accuracy (resolution) are different.
1. Inkjet printers can output transparencies and sulfuric acid paper. It prints unusually bright color document patterns and black and white files in color ink, but the output film has a low density and poor quality. Can only be used for screen printing negatives of text patterns.
2. The laser printer can output transparent film and sulfuric acid paper. It adopts the principle of electrostatic imaging to make the toner adhere to the image area on the surface of the photoconductor to form an image. After heating, the toner is melted and fixed on the transparent substrate. The image is carbon. Powder particle composition, coarse grain, uneven layer, low image density, large dot loss, large dot deformation, large number of holes, black spots, dirty version, can be used for pattern text block printing original, can not be used as color mesh original Negative film.
3. The laser image aligning machine is a laser electronic color separation screening system which is a laser modulator or a galvanometer system. The computer is controlled to pass the laser or is prevented from being exposed to the recorded silver salt film to form an image. After development, a high-precision dot silver salt negative film is obtained. The film output of the laser imagesetter has high resolution, high density, clean dots, clear lines, clear background and rich layers. It is the best negative film for mesh printing.