PART B. Design and Manufacturing Requirements

1. Colors

How to Specify a Color
Hue (color), value (lightness), and chroma (intensity) are characteristics used to describe tile appearance of all individual color. It is often useful to think of it as a three dimensional color space.

Either Subtractive or Additive methods can create colors. The simplest example to demonstrate Additive methods is the Television where primary colors of Red, Green and Blue are mixed to produce white light and other spectral variants.

Process printing uses a subtractive method where the Secondary colors of Yellow, Magenta, Cyan are combined to produce a theoretical black. Due to impurities the result is muddy in appearance and a fourth black printer is added to darken shadow areas and add contrast.



Color Wheels
One of the special challenges related to vitreous transfers is the prediction of the final color appearance after firing. Color wheels are decals printed with a variety of colors representing a broad range of available colors within a frit system. They are used for making tests on different substrates and firing variables to specifying color. We have developed standard color pallets for glass, ceramic over-glaze, and ceramic in-glaze firing temperatures. These colors are presented on their respective color wheels for ease of selection and firing tests. Color wheel decals for each of the three pallets are available upon request.

Pantone™ Matching System - PMS
A number of color identification systems have been produced to define and communicate color. The Pantone™ System has been established as a popular system in the US and is useful as a visual reference. Unique numbers have been assigned to a broad range of colors and are available in many media including charts and reference books.

Originally developed by American artist A. H. Munsell, this system applies a logical system to the numbering of each color based on assigning letters and numbers to various steps on a three dimensional color chart.

A variety of instruments are available to measure color and numerically encode the results. Most rely on sophisticated optical technology, Communicate with color formulation software and present the data in L*A*B* , CIE, or other three dimensional notations. A recent innovation is the Colortron which is a color measurement device designed to integrate into the popular software used today.

The value of color we see is a direct function of the source of light illuminating the surface. Even small variations in light sources can have a dramatic effect on certain colors. Viewing booths and special lamps are available which offer ideal viewing conditions as are indicators which offer a simple method of checking existing viewing conditions.

Flux Coating
Flux coating is the printing of a clear or colorless frit as a last color. It effectively adds a layer of melted -lass or -laze to the fired surface. It is often done to increase durability (chemical or abrasion resistance), seal toxic metal, improve process tolerance to Firing variables, or offer the appearance of a spot lacquer or gloss to the image.

Color Development Process Technique
When developing and formulating colors and test firing decals for our customers, we simulate the firing conditions with our kilns and temperature controls. We have both gas and electric kilns. With this equipment can control peak temperatures with cones using a Dawson Kiln Sitter or with thermocouples using either multi-step programmable ramp soak controllers or rate controlled high temperature limit shut off.

It is always important to specify the firing profile whenever a new project is initiated. In addition to firing profiles, color development also requires substrate samples. Since the color appearance of a decal is affected by the ware onto which it is fired, It is always advisable to send ware samples along with art specification whenever proofing is to be performed. In cases where pieces or too large or expensive, sample tiles can often be produced to provide a similar surface. We can also use a diamond saw and hammer to produce smaller pieces when samples are sparse.

Color Matching
Our color lab is capable of matching thousands of visible colors, appearances and special effects. There are still a few challenges left, notably in the florescent category of hot green or pink, and very clean magenta and cyan.

It may help to understand that these colors are composed of a variety of components including frit, pigment, and opacifiers, matting agents, stabilizers and more. Of these, the following two bear closer examination.

This is the part that melts and fuses. It is, in a word, glass. It has been processed into a powder and contains a variety of components of its own. Each is designed to achieve a particular quality.

This is the part that produces what we typically refer to as the coloring. It is always inorganic, and usually a blend of minerals or metal oxides. Organic pigments like animal dyes or petroleum based products simply will not survive the intense heat the decals are subjected to in the firing process.

Conventional halftone printing permits a single color to appear as tonal graduations by controlling the dot size of uniform frequency. Halftone screen rulings are represented as lines or dots per inch or centimeter.

2. Artwork

This award winning team of artists and designers was assembled in response to the growing need for innovative and affordable graphics for the glass and ceramic industries. Their talents and creative styles are a resource for clients who want to take their ideas to the next phase of development; rough sketches or full color comps. From here detailed pencil sketches are produced, refined and then rendered as final art. The process includes integrated feedback and a client-approved outline. Our artists are industry aware, reducing the possibility of contracting for art which is not translatable to Your specific needs.

Creating a sheet layout
There are three general classifications of layouts- UNIFORM, COMPOUND and IMBEDDED. One important factor in laying out a sheet is to allow adequate space for the cutting of the decals. Leave a minimum of 1/4" between images if the decals are to be cut by hand or stitched and 3/8" to 1/2" between decals if they are to be die cut.

Uniform- Regular rows and columns of a single item.

Compound- Variation of sizes and shapes.

Embedded- Compound layout where decals fit inside each other

Color Separation Options
The following identifies three major categories of artwork and describes the color separation techniques most closely related to them. It is offered in response to your many requests for a guideline to use when evaluating the options related to ceramic decal reproduction. Although the principles are fundamentally valid for most printing processes, please understand that this is a simplification. In practice, artwork, often does not fall into a discreet category. In those cases, a multitude of variations that are well beyond the limited scope of this discussion are required.

Categories of Original Art

Line Art
Graphic presentation of subjects with clearly defined areas of solid colors with little or no tonal variation.

Artwork produced by the application of multiple shades of color, blended together

A likeness obtained by photography; continuous tone images.


Typical Separation Techniques

Printing of one or more drawings or hand cut stencils that define the relative placement of each solid color. Examples- Cartoons, logos.

Photo- Mechanical
Printing combinations of solid and toned art together that create an interpretation of the original . This can employ halftones, pointillism, posterization, or stipple techniques to create shadows and highlights or intersperse dots to blend into new tones. Examples- Textile prints and floral, Serigraphs and Art Prints.

Printing of subtractive tones of the 4 primary colors, usually from laser scanned electronically produced separations to create a reproduction of the original but may include discrete enhancement individual colors and or digital manipulation of composition. Examples-Fine Art Reproduction, Collector Plates.

Advantages / Limitations of the Separation Techniques

Mechanical is most economical for up to 5 or 6 colors. Bright solid colors work best. Easy to match local color. Simple to produce multiple color variations.

Photomechanical makes it, simple to print multiple color variations using the same art and separations. It is often less costly to engineer multiple size adaptations without creating new original artwork. Elaborate artwork can require 15 colors or more causing both separation and printing costs to rise dramatically.

Process is the most faithful Graphic reproduction of original artwork. The manipulation of size and or color may require new art and or photography. Recent technology permits impressive new opportunities but cost is a significant factor. It is most difficult to match local color without adding additional color imprints.


Camera ready artwork

We can work from concept sketches, ideas, or descriptive text but "camera ready" is a term that we use to describe any art work that is presented in a manner that can be directly photographed without other composition, preparation, or manipulation. Line art does not need to be actual size, as long as it is to scale (larger is generally better than smaller). We can support Your art or development needs from virtually any level you desire, but art supplied in camera ready form usually requires fewer questions and alterations, resulting in faster service and reduced cost. For a complete discussion on types of art work and color separation techniques, please refer to: "Color Separation Options."

Specifications for customer supplied separations

Film Positive- emulsion up, right read or film Negative- emulsion down, right read.

Dot Angle
Yellow 90° Y Magenta 45° Y Cyan 105° Y Black 75°

Film size should comply with the print area of one of our three sheets; 10x13 (9x12) • 13x20 (12x19) • 20x26 (19x25). 300dpi is the preferred resolution for process work. The line count for halftone work should be either 100, 120 or 150-line screen. 150 line should be used for collector quality process work or any art with fine line detail. 120 line is a standard line count for halftone graphics not requiring fine detail and line art with gradated tones. Line art without gradated tones or fine line detail can be reproduced using a 100-line screen. Hard copy or
Match-print must accompany all films.

Some basic rules to follow when preparing separations requiring spot colors are as follows. Gold and cadmium bearing colors must be knocked out of process yellow and magenta to avoid contamination between the frit systems. In most cases cyan and black can still be overprinted for shadowing. Precious metals must be spread and printed first. Dot angle for spot colors is determined by the process color's) it is replacing. All images are unique to some extent when dealing with spot colors for enhancement of the image.

We will review your art and supply detailed instructions as to the treatment of spot colors or perform the required work on our computer systems.

Electronic medium
The most cost effective way to supply art is electronically. Line art should be supplied in layers, using any of the more popular Macintosh based graphics programs. Layers should be generated and identified by PMS colors to ensure accurate separation during output. When type is used within the graphic, a copy of the fonts should be included on the disk. Hard copy of image should accompany all disks.

Four color process work should be separated and saved in C.M.Y.K. Additional spot colors, used to enhance the art, should be saved on additional layers and knocked out of one or all of the C.M.Y.K where needed. Review of the art is needed to determine what spot colors will be needed and direction will be given where they are to be knocked out. See Trapping, Chokes and Spread for correct knock out requirements.

Trapping, Chokes and Spreads
Whether supplying film or disk, trapping guidelines must be followed to assure proper color fit on press. When trapping a spot color a to four-color process background a two pixel choke is used for the knock out. This insures a smooth transition between the colors, thus eliminating a hard trap line. For line art, a minimum .25 pt spread should be used when trapping solid or gradated colors to line art, but a .5 pt spread is preferred. Light colors always trap to dark colors.

3. Proofing, Photo-cals™ and Printing

Proofing can be accomplished in a number of ways including the printing of a short run which produces a physical sample of the decal creating a standard to which all future printing editions would be compared. Other options include Digital Color Proofs and a special variation which we term a Photo-call™ a non-firing decal.

Photo-call is a computer generated full color, cold application, water slide off decal. It can be produced very quickly, in small quantities, at a very reasonable cost. Multiple iterations and almost unlimited freedom in image editing are also possible. It is ideal for models, photography samples, prototypes, trade show samples, dinnerware fits, focus group testing, proofs, and a host of other product development needs.

Changes in size, color, or composition can be selectively and easily accomplished creating the advantage of being able to see and test multiple iterations on your product prior to committing to production of decals or decorated product. We can't imagine more unlimited freedom with image editing or flexible options.

We can work from your drawing, transparency, or electronic data. We can handle a broad range of media including all popular magnetic floppy discs, 44 Mb or 45 Mb cartridges, optical discs, high speed modem, and more.

Modern screen-printing typically uses a photographic stencil which covers the non image areas. This leaves image areas open to accept ink. The screen material is usually a monofilament fabric of either polyester or stainless steel. Printing is accomplished by forcing the ink through the screen area with a rubber or urethane squeegee. Heavy ink consistency and course halftones can restrict reproduction quality. Recent developments now permit fine halftone rulings of 150 line and greater. Screen-printing offers higher coating thickness than lithography, which results in consistent and reliable results, needed for today's textures and other varied aesthetic appearances. Ink thickness is controlled by screen mesh, stencil thickness, ink formulation and press adjustments.

4. Special Purpose and Special Effects


Uni-Mark™ decals are applied onto bisque ware with the help of a bonding solution. The ware is then glazed and the piece is fired. Uni-Mark™ can be applied over raw glaze as well. Either way, the result is a once fired product with a permanent decoration and glaze.

Application to bisque ware
A bonding solution is brushed or sprayed onto the bisque ware so the surface of the ware will be less porous. This allows the decal to adhere to the surface . Uni-Mark™ decals are applied to the treated bisque through traditional water-slide methods (See
Vitrical™ for additional application information). It is very important that the decal be applied to the ware while the bonding solution is still wet. The decal must then be squeezed to ensure there are no air pockets between the decal and solution. Once the decal is in place, any excess solution should be removed with a soft cloth. Bonding solution is available through most ceramic vendors. Once the decal has been applied, the ware should be allowed to stand for twelve hours to assure proper adhesion. There is an interaction between the bonding solution and cover-coat of the decal. The effect is to soften the cover-coat, causing adhesion between the transfer and the bisque. After twelve hours, the ware is ready for glazing. In order to help the glaze completely cover the cover-coat of the decal, it is essential to use a wetting agent in the glaze. The additive should be between 1/2 and I% by weight to the slop weight of the glaze.

Application to raw glaze
Uni-Mark™ decals can also be applied to raw glaze. The glaze is applied to the bisque ware and allowed to dry. The glaze surface will need to be sealed with a binder as well. Uni-Mark™ decals are then applied over the raw glaze as described previously.

Once Uni-Mark™ decals have been applied and allowed to dry, the ware, decal, and glaze are then matured in a single firing. The time/temperature curve of the firing cycle will depend on the type of ware and glaze that you are using (See Proper Firing). Normally, the temperature range of the decals is between 1800 and 2000°F.


These water-slide decals will create an embossed or relief appearance to glazed china, pottery, and tile. The embossed area can be colored to fit your specific needs. MIGRA-CAL™ decals are designed to be applied to the fired glaze surface of your ware. They should then be re-fired in the range of 1800-2000° F., depending upon glaze composition and the amount of relief you want to achieve. The intensity of relief produced by this product is both a function of glaze composition and firing temperature. Several trial runs may be required to achieve the desired effect; however, repeatability is quite reliable as long as temperature and glaze composition are consistent. This effect is achieved because the materials used in the decal change the wetting characteristics of the glaze. The result is that the glaze will pull away from the decorated surface areas. The decorated surface will present depressed features in decal image areas, thereby producing an embossed or glaze relief in the non-image areas. This type of effect is especially useful for architectural purposes.

MIGRA-CAL™ decals are applied onto glazed ware using traditional water-slide/squeegee methods (for more information on application, see
Vitrical™). Once dry, the decals are then fired producing an embossed effect.

Phone: Phone: (215) 493-8449  Fax: (215) 325-0137  
PO BOX 28 Morrisville, Pa 19067  E-mail   2004 MOLFRAN LLC