Have you done all these pre press inspections

2022-08-21
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Have you done all these pre press inspections?

many inspections need to be done in the early stage of printing, as listed below:

I: screen inspection:

picture inspection: on the calibrated screen, check the color and quality of the picture. How about the layering and clarity of the picture? It can be improved by color adjustment or sharpness emphasis. If there is any impurity, stain, or something inconsistent with the content of the picture, you can use a rubber stamp to repair it. Are there any hard color patches connected (such traces are easy to occur when the image is repaired with a rubber stamp and the operation is incorrect)? It can be treated with fuzzy filter

color block check: check the color matching in the typesetting file. In the typesetting file, check whether the colors of color blocks, lines and words look coordinated, for example, whether white words that are not easy to see are used on the light background

II: check the printout:

check the printable content. The printout should be as close to the future proofing as possible. Specifically:

1: print according to the size set during typesetting, and don't reduce it. This is the size of proofing in the future. If your printer can't print large format documents, print in blocks. There is overlap between blocks, and connect them with transparent glue, The overlapping parts are accurately aligned. 2: Before printing, it is best to draw corner lines, gauge lines, broken lines, etc., because the printer cannot automatically output reference lines like the Phototypesetter. After printing, it is necessary to cut, fold and make a model of the finished product for inspection according to these reference lines, which is particularly necessary for printed products with complex structures such as cartons and envelopes

III: file inspection:

image inspection: check the file format, which can only be TIF or EPS format before printing. Color mode, color picture is CMYK, monochrome picture is grayscale mode. RGB mode is not allowed. The resolution should reach 300dpi. Delete redundant spot color channels and alpha channels and delete redundant paths. Check the color value of black lines and small black blocks. Generally, it should be monochromatic Black: c0m0y0k100

typesetting file:

check size:

1: does the page size meet the requirements of the finished product

2: parts with the same size often appear in printed matter, such as the pages of the album, the sides of the folding page, and the surfaces of the operating parts of the cube paper products that are relatively corroded by the friction and wear tester. In the typesetting software, they should be the same size after bleeding, and their bleeding conditions may be different, which is easy to cause errors. For this, it is necessary to use the numerical function of the typesetting software to accurately check, Subtract the amount of bleeding from the width of each side to calculate its size in the finished product

3: on some printed matters, there should be differences in the seemingly same size. For example, the tongue of the carton should be a little narrower than the opening, so that it can be inserted

4: some products are composed of several parts, and their printing materials are different, so they are made in different documents, such as the envelope and inner text of the album, the shell and inner support of the package. When checking, open these documents and compare the dimensions of each part

5: whether the page of spot color and die cutting is as large as the four-color page, and whether the spot color image and text, die cutting line can be registered with the four-color image and text

bleeding:

check along all cutting lines and broken lines, and pay attention to the following problems:

1: whether the pictures, color patches and lines bleed, and whether the objects on the cutting line bleed

2: is there any important content out of the page after the image bleeding

3: whether the content that should not bleed is too close to the cutting line. 7. The force value, displacement, stiffness, curve and other data can be printed into a standard experimental report; Easy to cut (such as corner icon, page number)

color:

1: Typesetting documents can set color modes for various fill colors and outline colors respectively, but only CMYK mode (for color mode) or gray mode (for monochrome mode) can be used before printing. The most easily misused color mode is RGB, and its printing results are unpredictable

2: Black errors are not easy to detect. One is r0g0b0, which is usually generated when copying black objects from other software. The other is registration color. Its color value is c100m100y100k100, which can only be used to draw reference lines outside the page for printers to check the four-color registration. The result of these two kinds of black printing will be four-color overprint, which is easy to produce ghosting due to inaccurate registration, It is particularly obvious on thin lines. Black lines, words and graphics should generally use c0m0y0k100 monochrome black

3: if the edge of the picture is required to be fused with the color block below, they should have the same CMYK color value. If they just look fused on the screen and the color value is different, stiff edges will appear during printing

4: check whether superimposed colors and light colors are misused

5: in many typesetting software, when a color on the palette is changed, the color block, lines and words using this color (such as the clamping surface of the fixture of the sample such as plastic film and fiber wire) will change color. Pay attention to this

6: pay attention to whether the figure has a very thin outline that is difficult to detect and should not exist

7: if the figure should have a contour, pay attention to whether the color of the contour is correct. Because many contours are thin, misuse of printing, overprint, RGB color is often ignored

link:

each typesetting software has a link dialog box from which the basic situation of the picture can be checked

1: is the picture missing? Or did you forget the link after the picture was renamed? This will make the picture unable to be output in high resolution

2: did you misuse RGB and other color modes that are not allowed before printing? Although RGB pictures are displayed normally in typesetting software, there will be errors in proofing

3: whether there are redundant channels or paths, which may make the image output incomplete

4: did you misuse formats that are not allowed before printing, such as JPG

graphic style:

1: pay attention to the abnormal changes of text paragraphs, such as paragraph overflow, graphic dislocation

2: is there only one word in the last line of the paragraph

3: whether some English letters use Chinese fonts, which is very awkward

4: whether there are garbled codes and redundant spaces

5: is there any content that violates the prohibition of typesetting? Most punctuation marks cannot be at the beginning of the line (such as comma, period, stop sign, semicolon, colon, exclamation point, right quotation mark, right parenthesis, right book name), some punctuation marks cannot be at the end of the line (such as left quotation mark, left parenthesis, left book name), and some characters cannot be opened when branches are broken (such as English numbers, dashes, ellipsis)

6: whether there are incorrect half width punctuation marks (such as commas, periods, semicolons, colons, exclamation points, quotation marks, parentheses in English)

7: whether there is any content that should be aligned but not aligned (such as the left-right alignment of the book's body page number, the up-down alignment of the catalogue page number, and the up-down left-right alignment of the table content)

8: is there any content that should adopt a unified style but is not unified (such as the decoration of each page of the book block, notes, the style of the title at the same level is inconsistent, and the text and paragraph styles in the same article are inconsistent)

9: is the text suppressed by pictures and color patches? Or is the distance between the text and them appropriate

10: other problems that do not conform to the typesetting rules

IV: film and proofing inspection:

(I): film inspection:

1: check the number of films. Four color documents should have four films. If there is spot color, there should be one more film for each spot color. Die cutting, embossing, hot stamping, etc. also need separate films like spot color

2: identify the ink color corresponding to each film, which can be seen by comparing the proofing. There are measurement and control strips on the edge of proofing, which are a series of color blocks. Their color values are known, and they are printed by various color films. If the first grid of measurement and control strips on proofing is C100, the second grid is M100, the third grid is Y100, the fourth grid is c100m power stop (red) 100, the fifth grid is m100y100, and the sixth grid is c100y100, The seventh grid is c100m100y100, and the eighth grid is k100. It can be inferred that on the film corresponding to C (cyan ink), the first, fourth, sixth, and seventh grids of the measurement and control strip are the field, and the second, third, fifth, and eighth grids are blank. On the film corresponding to m (magenta ink), each two, four, five, seven grids of the measurement and control strip is the field, and each one, three, six, and eight grids are blank. On the film corresponding to y (yellow ink), the third, fifth, and sixth grids of the measurement and control strip are blank, Seven boxes are on-site, and the first, second, fourth and eighth boxes are blank. On the film corresponding to K (black ink), only the eighth box of the measurement and control strip is on-site, and the rest are blank. As for spot color, die-cutting, embossing, hot stamping and other films, it is easy to see from the content of graphics and texts

3: to check the film registration, it is best to use a special sample table with ground glass on the table and white light source under it, or use a white ordinary table, put a film with relatively complete graphic content (usually the film corresponding to black ink) on the table, stack other color films and spot color, die-cutting and convex films one by one, and align the corner lines of the four corners of the upper and lower films, Check whether their contents are aligned

4: check whether there are scratches, dirty spots, virtual light spots, laser lines and creases on the film

5: check the number of lines added and various color angles. Experienced designers can see whether these parameters meet the requirements with the naked eye. They can also check them with a special 10x magnifying glass for printing, with scales on it

6: check the dot ratio on the gray scale at the edge of the film. Each color block of the gray scale has a specified dot ratio. The actual dot ratio can be seen under a 10x magnifying glass, and the deviation should not exceed 2%

7: if possible, check whether the field density can meet the printing requirements with a densimeter, which should be above 3 or 4

(II) proofing inspection:

1: check the contents of proofing, just like checking the printout

2: check the size of the finished product. There are angular lines at each corner of the proofing, which are usually double lines. The line on the inner side is the cutting mark. Measure the distance between the cutting mark on the left and the cutting mark on the right, which is the width of the finished product. Measure the distance between the cutting mark on the upper side and the cutting mark on the lower side, which is the height of the finished product. It depends on whether the size of the finished product reflected by these cutting marks meets your requirements

3: make a finished product model, cut and proofing along the cutting mark with a ruler and a art knife, and then fold it into the appearance of the finished product along the folding mark - especially for three-dimensional printed materials such as cartons - will there be any problems in processing after inspection

check film points, proofing appearance, and finished product model made with proofing

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