Outside Diameter (116mm)
116 mm is the maximum diameter that the manufacturer can print images.

Film Fail Issues:

• Elliptical - the outer diameter of the film is not a true circle. Not all points on the outer edge of the film measure the same distance from the center of the disc.
• Exceeds 116mm - The film extends past the 116mm measurement. This can happen uniformly or in a elliptical shape. (During printing, this causes bleeding past the edge of the disc [120mm] and will eventually cut the screen after a few passes of the squeegee.)

Inside Diameter (47mm @ Mirror Band)
The beginning area of mastering data which is located adjacent to the high gloss area of metal (mirror band).

Film Fail Issues:

• Elliptical - The film is not a true circle at the area that prints on the outside edge of the mirror band. Printing will appear as if the design was not centered in the disc before printing.

Centerhole (18mm)
The innermost location of the disc located in the center of the non-metalized portion.

Film Fail Issues:

• Elliptical - Design is not a true circle. Film does not fit evenly around the centerhole of the disc.
• Prints into centerhole - Design measures smaller than the 18mm and will print into the relieved area of the center. Printing will cause damage to the machine and will leak ink under the disc where it will not cure. (Ink will remain wet and cause the discs to stick together when they are returned to spindles.)

Groove or Knock-Out Ring (32.5mm - 37.0mm)
Actual indentation or relieved are in the disc, located near the center of the disc, just inside the last metalized portion. Printing is not allowed in the Groove or Knock-Out Ring area of the disc between 32.5mm diameter and 37.0mm diameter.

Film Fail Issues:

• Print into the Groove or Elliptical - The groove area on the film does not measure 2.25mm in width, or is elliptical and prints unevenly into the groove area. (Ink will remain uncured if printed in this area due to the lower surface level. Ink will remain wet and cause damage to the discs when they are returned to spindles.)
• No Groove - The design does not have a reverse image of the groove (2.25mm) taken out of the film. (Cannot use as this will damage both printing machines and the discs.)

Font Size (Minimum 4 pt. Bold)
The height of the letters, both capital and lower case, should not fall below the size indicated above. Must be measurable with gauge. Use a font that does not include thin serifs or scripts.

Font Size Dropped Out (Minimum 6pt. Bold)
Text that is "taken out" or reversed out of a design area and looks as though it has been printed in the metal (silver) area of the disc. Using fonts smaller than the required 6pt. Bold have a tendency to close as the ink spreads during printing. Registration is difficult and can easily appear misregistered if the font is small and thin.

Line Width (Minimum .50pt.)
The size of the lines that are reversed out of the film and appear to print in the metal (silver) area of the disc. Includes the lines in fonts, logos, and placed images.

The size of any solid line that is printed must also be .50pt. or larger.

Film Density (Blackness)
Film should appear completely black when placed on a light table. When creating a screen, the film is subjected to an extremely bright halogen light source that burns for a pre-determined time. If there are any weak or non-opaque areas where the light is not completely blocked, the exposure unit will "see" through the film and will not create a complete image on the screen.

Film Quality (Scratches/Pinholes-free)
Film should be of high quality without any scratches, creases or folds. Scratches, creases, or folds will not enable the film to lay flat on the screen, causing an uneven burn and thus an incomplete screen. Pinholes are portions of a halftone or solid that are missing a part of their design information. There is not a dot or unit of dots in a pinhole area. This lack of dot(s) can cause image loss or defective appearance.

Film Alignment
Film alignment problems occur when the film pieces within the same work order will not align properly to themselves. Dropped out areas might not match up at the appropriate places. Common causes are: stretching of the film during the developing or during imaging. The image setter getting bumped during the setting can also cause this problem.

Trap (.50pt.)
A spread (oversized) of the image that prints at the start of the film sequence (010, 020, etc.) usually in the lighter color. The spread of the light color goes under the images that print last or in the darker color. Overlapping of the lighter colors by the darker colors is done to prevent metal from showing around the edges (or letters, for example) as the machines adjust during printing.

Tonal Range (20% - 80%)
The measurement of the screen value in any one given place. Less than 20% concentration of dots will cause dot loss during printing and parts of the image disappear. Values greater than 80% concentration of dots will cause dot gain during printing and parts of the image clump together and appear splotchy. Can occur in halftones, solid screen backgrounds, and graduated fades.

Halftone/LPI
The amount of blank spaces that are placed in between the rows of dots that are used to create a halftone (photo image) or screened areas. Will appear as clear on film. Dot size is relative and automatically controlled by the outputting computer.

Silk-screen - 85 LPI
Due to the use of woven fibers that make the screens, the dot size must be larger and the spaces between them greater in an effort to give the emulsion a better chance to produce the image. Some loss of image detail and delicateness can occur, although higher count mesh enables some gain in intricate details.

Offset - 150+ LPI
The use of aluminum plates instead of the screens allows for a higher LPI to be used for offset printing. The higher the LPI, the fewer spaces of clear film which create closer rows of dots producing a higher resolution image. Without any "holes" in the plate for the design to slip into, the image that is burned is more complete and detailed.

Prints Into The Mirror Band
Certain inks are mixed with large proportions of light based ink. Red and yellow are the two most common mixing inks effected by refracted light. The mirror band is a high polished area, whereas the metal containing data is a refractive or buff finish. Colors that are made with light shades (light based inks) can be effected by the mirror band and hub. They will turn dark when printed over the band if not blocked by a base. In certain cases, they appear as if a different ink has been used.

Moire
A pattern resulting from the use of inappropriate film angles. Rows of dots in a piece of film conflict with those in another piece and do not lay in corresponding rows. The effect is a distinctive box-like shape with hazy edges. Moire can "walk" or "grow" as the film is rotated on a center axis. Pattern can be caused by the angle of the screen versus the angle of the rows of dots in a single piece of film. Appearance is more like striations instead of boxes.

Emulsion
The side of the film that was exposed to the laser in order to cut the image. Can be tested by scrapping the film with the image legible.

Silk-screen - Emulsion Up

Offset - Emulsion Down

Keylines
Guides or boundary lines. They usually mark the centerhole, groove, and outside diameter. They should NOT be on the film image as there is no masking system in the screen making process.