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Rolls of lithographer's tape (these rolls are made by 3M). The roll in the back is 1/4 inch, the one in the front, 1/2 inch width. These products are often called "Rubylith" tape because Rubylith has become a generic term for coloured masking films. Rubylith two rolls 2012.jpg
Rolls of lithographer's tape (these rolls are made by 3M). The roll in the back is 1/4 inch, the one in the front, 1/2 inch width. These products are often called "Rubylith" tape because Rubylith has become a generic term for coloured masking films.

Rubylith is a brand of masking film, invented and trademarked by the Ulano Corporation. Today the brand has become genericized to the point that it has become synonymous with all coloured masking films.

Photomask opaque plate or film with holes or transparencies that allow light to shine through in a defined pattern

A photomask is an opaque plate with holes or transparencies that allow light to shine through in a defined pattern. They are commonly used in photolithography.

Rubylith consists of two films sandwiched together. The bottom layer is a clear polyester backing sheet; the top layer is a translucent, red-(ruby-)coloured, sheet. The top layer can be cut with a knife and peeled away from the bottom layer. The top layer's colour is light-safe for orthochromatic films (which are sensitive to blue and green light but insensitive to red light).

Polyester category of polymers

Polyester is a category of polymers that contain the ester functional group in their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in the cutin of plant cuticles, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. The material is used extensively in clothing.

Rubylith is used in many areas of graphic design, typically to produce masks for various printing techniques. For example it is often used to mask off areas of a design when using a photoresist to produce printing plates for offset lithography or gravure. It is also frequently used during screen-printing.

Graphic design the visual design of content in different media

Graphic design is the process of visual communication and problem-solving through the use of typography, photography and illustration. The field is considered a subset of visual communication and communication design, but sometimes the term "graphic design" is used synonymously. Graphic designers create and combine symbols, images and text to form visual representations of ideas and messages. They use typography, visual arts and page layout techniques to create visual compositions. Common uses of graphic design include corporate design, editorial design, wayfinding or environmental design, advertising, web design, communication design, product packaging and signage.


A photoresist is a light-sensitive material used in several processes, such as photolithography and photoengraving, to form a patterned coating on a surface. This process is crucial in the electronic industry.

Ulano also produces a yellow coloured, masking film called Amberlith, that is not light safe but easier to use for masking when not employing a photoresist.

Rubylith was used in the early days of semiconductors and integrated circuits. [1] The physical layouts of the first generations of Intel microprocessors (the Intel 4004 [2] and the Intel 8008 (nee 1201)) were first hand drawn on graph paper. A technician would then use a coordinatograph to precisely cut the rubylith and a knife to peel the appropriate sections away. The finished Rubylith mechanical masters were then photo reduced up to 100 times and then step and repeated on to glass plates for production use. Shortly after the 8008, Intel started using Calma's computer-aided design system that ran on a Data General minicomputer; the output masters may have stayed rubylith for a time, but other output options became available. Bell Telephone Laboratories, for example, had a high-resolution photoplotter. [3] The integrated circuit industry left rubylith for better technologies.

Intel 4004 4-bit central processing unit

The Intel 4004 is a 4-bit central processing unit (CPU) released by Intel Corporation in 1971. It was the first commercially available microprocessor by Intel, and the first in a long line of Intel CPUs.

Intel 8008 byte-oriented microprocessor

The Intel 8008 is an early byte-oriented microprocessor designed and manufactured by Intel and introduced in April 1972. It is an 8-bit CPU with an external 14-bit address bus that could address 16 KB of memory. Originally known as the 1201, the chip was commissioned by Computer Terminal Corporation (CTC) to implement an instruction set of their design for their Datapoint 2200 programmable terminal. As the chip was delayed and did not meet CTC's performance goals, the 2200 ended up using CTC's own TTL-based CPU instead. An agreement permitted Intel to market the chip to other customers after Seiko expressed an interest in using it for a calculator.

A coordinatograph is an instrument which mechanically plots X and Y coordinates onto a surface, such as in compiling maps or in plotting control points such as in electronic circuit design.

Certain digital image editing programs that have masking features may use a red overlay to designate masked areas, mimicking the use of actual Rubylith film.

Image editing processes of altering images, digital or traditional photos

Image editing encompasses the processes of altering images, whether they are digital photographs, traditional photo-chemical photographs, or illustrations. Traditional analog image editing is known as photo retouching, using tools such as an airbrush to modify photographs, or editing illustrations with any traditional art medium. Graphic software programs, which can be broadly grouped into vector graphics editors, raster graphics editors, and 3D modelers, are the primary tools with which a user may manipulate, enhance, and transform images. Many image editing programs are also used to render or create computer art from scratch.

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Intel 8080 8-bit microprocessor

The Intel 8080 ("eighty-eighty") was the second 8-bit microprocessor designed and manufactured by Intel and was released in April 1974. It is an extended and enhanced variant of the earlier 8008 design, although without binary compatibility. The initial specified clock frequency limit was 2 MHz, and with common instructions using 4, 5, 7, 10, or 11 cycles this meant that it operated at a typical speed of a few hundred thousand instructions per second. A faster variant 8080A-1 became available later with clock frequency limit up to 3.125 MHz.

Integrated circuit electronic circuit manufactured by lithography; set of electronic circuits on one small flat piece (or "chip") of semiconductor material, normally silicon

An integrated circuit or monolithic integrated circuit is a set of electronic circuits on one small flat piece of semiconductor material that is normally silicon. The integration of large numbers of tiny transistors into a small chip results in circuits that are orders of magnitude smaller, cheaper, and faster than those constructed of discrete electronic components. The IC's mass production capability, reliability and building-block approach to circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are now used in virtually all electronic equipment and have revolutionized the world of electronics. Computers, mobile phones, and other digital home appliances are now inextricable parts of the structure of modern societies, made possible by the small size and low cost of ICs.

Photolithography, also termed optical lithography or UV lithography, is a process used in microfabrication to pattern parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate. A series of chemical treatments then either engraves the exposure pattern into the material or enables deposition of a new material in the desired pattern upon the material underneath the photo resist. For example, in complex integrated circuits, a modern CMOS wafer will go through the photolithographic cycle up to 50 times.

In electronics design, tape-out or tapeout is the final result of the design process for integrated circuits or printed circuit boards before they are sent for manufacturing. The tapeout is specifically the point at which the graphic for the photomask of the circuit is sent to the fabrication facility. A synonym used at IBM is RIT. IBM differentiates between RIT-A for the non-metallic structures and RIT-B for the metal layers.

Printed circuit board board to support and connect electronic components

A printed circuit board (PCB) mechanically supports and electrically connects electronic components or electrical components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.

A photoplotter is a specialized electro-opto-mechanical machine that exposes a latent image on a medium, usually high-contrast monochromatic (black-and-white) photographic film, using a light source under computer control. Once the film has been exposed, it must be processed before it is ready for use.

Decal plastic, cloth, paper, or ceramic substrate that has a pattern or image printed on it

A decal or transfer is a plastic, cloth, paper or ceramic substrate that has printed on it a pattern or image that can be moved to another surface upon contact, usually with the aid of heat or water.

Gate array

A gate array is an approach to the design and manufacture of application-specific integrated circuits (ASICs) using a prefabricated chip with components that are later interconnected into logic devices according to a custom order by adding metal interconnect layers in the factory.

Photogravure printmaking technique

Photogravure is an intaglio printmaking or photo-mechanical process whereby a copper plate is grained and then coated with a light-sensitive gelatin tissue which had been exposed to a film positive, and then etched, resulting in a high quality intaglio plate that can reproduce detailed continuous tones of a photograph.


A safelight is a light source suitable for use in a photographic darkroom. It provides illumination only from parts of the visible spectrum to which the photographic material in use is nearly, or completely, insensitive.

Place and route is a stage in the design of printed circuit boards, integrated circuits, and field-programmable gate arrays. As implied by the name, it is composed of two steps, placement and routing. The first step, placement, involves deciding where to place all electronic components, circuitry, and logic elements in a generally limited amount of space. This is followed by routing, which decides the exact design of all the wires needed to connect the placed components. This step must implement all the desired connections while following the rules and limitations of the manufacturing process.

Photoengraving is a process that uses a light-sensitive photoresist applied to the surface to be engraved to create a mask that shields some areas during a subsequent operation which etches, dissolves, or otherwise removes some or all of the material from the unshielded areas. Normally applied to metal, it can also be used on glass, plastic and other materials.


A stepper is a device used in the manufacture of integrated circuits (ICs) that is similar in operation to a slide projector or a photographic enlarger. The term "stepper" is short for step-and-repeat camera. Steppers are an essential part of the complex process, called photolithography, that creates millions of microscopic circuit elements on the surface of tiny chips of silicon. These chips form the heart of ICs such as computer processors, memory chips, and many other devices.

Contact lithography, also known as contact printing, is a form of photolithography whereby the image to be printed is obtained by illumination of a photomask in direct contact with a substrate coated with an imaging photoresist layer.


LIGA is a German acronym for Lithographie, Galvanoformung, Abformung that describes a fabrication technology used to create high-aspect-ratio microstructures.

Photochemical machining

Photochemical machining (PCM), also known as photochemical milling or photo etching, is a chemical milling process used to fabricate sheet metal components using a photoresist and etchants to corrosively machine away selected areas. This process emerged in the 1960s as an offshoot of the printed circuit board industry. Photo etching can produce highly complex parts with very fine detail accurately and economically.

In integrated circuits, the stepping level or revision level is a version number that refers to the introduction or revision of one or more photolithographic photomasks within the set of photomasks that is used to pattern an integrated circuit. The term originated from the name of the equipment ("steppers") that exposes the photoresist to light. Integrated circuits have two primary classes of mask sets: 1. base layers that are used to build the structures that make up the logic such as transistors, and 2: metal layers that connect the logic together.


  1. "Intel's Accidental Revolution". CNET.
  2. "Intel family Processor Evolution" (PDF).
  3. Primary Pattern Generator discussed in Bell System Technical Journal, November 1970, volume 49 number 9.