Print Unevenness

This means unwanted variation in density, color or gloss in print. The size and intensity of the variations are measured. Print density variations (graininess 0.5-2 mm mottle 2-8 mm) are measured from an even black and/or cyan tone of at least 40% and as an average of eight images with a size of 51 x 51 mm.  

---

Kaufmann A, Koenig R, Lesemann D-E. Tissue print-immunoblotting reveals an uneven distribution of beet necrotic yellow vein and beet soil-borne viruses in sugar beet. Arch Virol 1992 126 329-335. 

Injection molding requires the barrel temperature to be about 350°C with a barrel pressure in excess of 138 MPa. The mold is maintained at 110°C to ensure uniform flow and high definition, and to discourage an uneven index of refraction, birefringence. The CD is about four one-hundredths of an inch (0.5 mm) thick. For prerecorded CDs, the PC is compression-molded on a stamper imprinted with the recorder information. This takes about 4 sec. Once the clear piece of polycarbonate is formed, a thin, reflective aluminum layer is sputtered onto the disc. Then, a thin acrylic layer is sprayed over the aluminum to protect it. The label is then printed onto the acrylic surface and the CD is complete. This process is described later in greater detail. 

Chemical synthesis produces dyes of varying particle size. When the dyes are applied in this form, uneven and spotty dyeing results, and the dyeing process may be slow and frequently accompanied by incomplete absorption [46], To assure high yield, good reproducibility, and faultless dyeing and printing in commercial use, especially when densely woven fabric or wound material is involved, the dye must be applied as a fine dispersion that is stable under the process conditions. 

A basecoat is applied to the panel after the filling operation. This is normally a pigmented lacquer or vinyl based material whose function is to hide the surface and provide a uniform color on which the grain will be printed. The basecoat is commonly applied by a curtain coater or more commonly with a roller coater. Obviously, skips in the basecoat, whether the result of deformed application rolls or panel unevenness, cannot be tolerated. Surface depressions not completely filled during the filling operation will not be basecoated and will appear as small white dots on the panel. 

Paper may be developed over a wide range of times with varying results. Up to a point, the longer paper is developed, the richer the gradation and overall print quality. Exposure and dilution can be adjusted to allow development from 1 to 7 minutes. Less than 1 minute can result in stains, streaks, and uneven development. However, the changes that take place after 3 minutes are often slight, even though they can at times make a difference. 

It is uncommon to find a shagreen fiike, but some were made at the hei t of the material s popularity in the twentieth century. They are not convindi as the natural product has a subtly uneven surface due to the denticles, while a ke is made of a printed laminate and is totally smooth. 

Occupational risk awareness and militancy among workers is unevenly distribute across the different sectors of economic activit the construction sector being the most militant followed by the metal soto- while tiie furniture and printing sector lag a long way behind. 

Coating consistency is crucial when producing screens for photorealistic printing. If the emulsion thickness is not controlled, it could lead to uneven ink deposits and visual distortions such as moire. For this reason, automatic coating devices are recommended. But if the cost of such devices is prohibitive, then maintain consistency by introducing as few variables as possible to the manual screen-coating process, including the number of personnel involved. 

Coloration broadly means dyeing and printing. The objective of dyeing is to achieve uniform coloration of the material, usually a prespecified color. Any significant difference in the color requested by the customer and the actual color and any unevenness of the color of a fabric is immediately apparent (Broadbent, 2001). Dyeing a textile material can be achieved in a number of different ways ... 

The construction method of the cloth as weave, knit, or bond influences the print result. Smooth cloths offer better definition and print clarity, compared to those fabrics with strong dimensionality and an uneven surface or incorporating slubs or raised hairs. Fiber and fabric types are considered in depth in Chapter 3 of this book. 

---