Perrotine printing

The perrotine is a block-printing machine invented by Perrot of Rouen in 1834, and practically speaking is the only successful mechanical device ever introduced for this purpose. For some reason or other it has rarely been used in England, but its value was almost immediately recognized on the Continent, and although block printing of all sorts has been replaced to such an enormous extent by roller printing, the perrotine is still largely employed in French, German and Italian works.

The construction of this ingenious machine is too complex to describe here without the aid of several detailed drawings, but its mode of action is roughly as follows: Three large blocks (3 ft. long by 3 to 5 in. wide), with the pattern cut or cast on them in relief, are brought to bear successively on the three faces of a specially constructed printing table over which the cloth passes (together with its backing of printers blanket) after each impression. The faces of the table are arranged at right angles to each other, and the blocks work in slides similarly placed, so that their engraved faces are perfectly parallel to the tables. Each block is moreover provided with its own particular colour trough, distributing brush, and woolen colour pad or sieve, and is supplied automatically with colour by these appliances during the whole time that the machine is in motion. The first effect of starting the machine is to cause the colour sieves, which have a reciprocating motion, to pass over, and receive a charge of colour from, the rollers, fixed to revolve, in the colour troughs. They then return to their original position between the tables and the printing blocks, coming in contact on the way with the distributing brushes, which spread the colour evenly over their entire surfaces. At this point the blocks advance and are gently pressed twice against the colour pads (or sieves) which then retreat once more towards the colour troughs. During this last movement the cloth to be printed is drawn forward over the first table, and, immediately the colour pads are sufficiently out of the way, the block advances and, with some force, stamps the first impression on it. The second block is now put into gear and the foregoing operations are repeated for both blocks, the cloth advancing, after each impression, a distance exactly equal to the width of the blocks. After the second block has made its impression the third comes into play in precisely the same way, so that as the cloth leaves the machines it's fully printed in three separate colours, each fitting into its proper place and completing the pattern. If necessary the forward movement of the cloth can be arrested without in any way interfering with the motion of the block, san arrangement which allows any insufficiently printed impression to be repeated in exactly the same place with a precision practically impossible in hand printing.

For certain classes of work the perrotine possesses great advantages over the hand-block; for not only is the rate of production greatly increased, but the joining up of the various impressions to each other is much more exacting fact, as a rule, no sign of a break in continuity of line can be noticed in well-executed work. On the other hand, however, the perrotine can only be applied to the production of patterns containing not more than three colours nor exceeding five inches in vertical repeat, whereas hand block printing can cope with patterns of almost any scale and continuing any number of colours. All things considered, therefore, the two processes cannot be compared on the same basis: the perrotine is best for work of a utilitarian character and the hand-block for decorative work in which the design only repeats every 15 to 20 in. and contains colours varying in number from one to a dozen

Read more...

Hand Block printing

This process, though considered by some to be the most artistic, is the earliest, simplest and slowest of all methods of printing.

In this process, a design is drawn upon, or transferred to, a prepared wooden block. A separate block is required for each distinct colour in the design.

A blockcutter carves out the wood around the heavier masses first, leaving the finer and more delicate work until the last so as to avoid any risk of injuring it during the cutting of the coarser parts. When finished, the block presents the appearance of flat relief carving, with the design standing out.

Fine details are very difficult to cut in wood, and, even when successfully cut, wear down very rapidly or break off in printing. They are therefore almost invariably built up in strips of brass or copper, bent to shape and driven edgewise into the flat surface of the block. This method is known as coppering.

To print the design on the fabric, the printer applies color to the block and presses it firmly and steadily on the cloth, ensuring a good impression by striking it smartly on the back with a wooden mallet. The second impression is made in the same way, the printer taking care to see that it fits exactly to the first, a point which he can make sure of by means of the pins with which the blocks are provided at each corner and which are arranged in such a way that when those at the right side or at the top of the block fall upon those at the left side or the bottom of the previous impression the two printings join up exactly and continue the pattern without a break. Each succeeding impression is made in precisely the same manner until the length of cloth is fully printed. When this is done it is wound over the drying rollers, thus bringing forward a fresh length to be treated similarly.

If the pattern contains several colours the cloth is usually first printed throughout with one, then dried, and printed with the second, the same operations being repeated until all the colours are printed.

Block printing by hand is a slow process it is, however, capable of yielding highly artistic results, some of which are unobtainable by any other method.

Read more...

Types of Printing

Often the first important factor is finding and using a printing with a strong reputation in the printing field. This printer should be able to help you or give advice on many of the decisions you might need to make while getting a printing job done. Ask around and do research on the internet if possible, compare services and prices between one printer and another.

Digital printing is a new and extremely effective form of printing. This form of printing eliminates the use of film and plates, and sends a digital file directly from a computer to the press. Digital printing is relatively fast compared to other printing methods, making it a convenient method for meeting deadlines and time restraints.

Electrostatic printing is a method similar to photocopying where colour sticks to a drum and is fused by heat to paper. Electrostatic printing is similar to digital printing in that both processes are useful and effective for short printing runs.

The most popular printing process used by most printers is Offset Lithography. This is a method where ink is used economically and set up time for the press is limited. This process is where ink is offset from metal plates to a rubber cylinder onto the paper. It is an affordable and most common method of printing.

One of the first and original printing methods is the Letterpress, which was developed by Gutenberg is 1440. This is where relief printing was first developed; the printed image is slightly raised from the surface of the plate - similar to a rubber stamp. This is a process performed by fewer printers as new technology takes over the printing world.

For the sharpest image, Engraving is a printing method where the image feels indented. This type of printing process is used for fine or expensive stationery, such as Law firm letterheads etc.

Thermography is a process which produces a raised image. This is a special powder or dust which adheres to wet ink. Then heat is applied, which makes the powder and the ink fuse to form a raised surface. This method is effective for stationery.

Reprographics is a general term which includes copying and duplicating. Most, if not all, printing companies offer a reprographics service, where they can take your original file or document and make duplicates of them.

Screen printing is a process where ink is forced through a silk screen. This is often used on non flat goods e.g. clothing, mugs, etc. This is a popular method for large scale billboards and signage.

Flexography is a printing process used for packaging products. This process uses rubber plates with printed areas raised in relief, the plates are flexible, making printing on many different materials possible, eg plastic bags, bottle labels, cardboard boxes, etc.

Gravure printing is an expensive high quality printing process which uses copper plates. This process is commonly used to print high quality large volume materials such as magazines, newspaper, catalogues and more.
The best methods to ensure you get the printing results you require are to ask questions of your printer. It is important that the printing process will deliver required results. Generally if you have chosen a good printer your products will look great.

Read more...

Textile printing

Textile printing is the process of applying colour to fabric in definite patterns or designs. In properly printed fabrics the colour is bonded with the fiber, so as to resist washing and friction. Textile printing is related to dyeing but, whereas in dyeing proper the whole fabric is uniformly covered with one colour, in printing one or more colours are applied to it in certain parts only, and in sharply defined patterns.
In printing, wooden blocks, stencils, engraved plates, rollers, or silkscreens are used to place colours on the fabric. Colourants used in printing contain dyes thickened to prevent the colour from spreading by capillary attraction beyond the limits of the pattern or design.
Traditional textile printing techniques may be broadly categorised into four styles:
• Direct printing, in which colourants containing dyes, thickeners, and the mordants or substances necessary for fixing the colour on the cloth are printed in the desired pattern.
• The printing of a mordant in the desired pattern prior to dyeing cloth; the color adheres only where the mordant was printed.
• Resist dyeing, in which a wax or other substance is printed onto fabric which is subsequently dyed. The waxed areas do not accept the dye, leaving uncoloured patterns against a coloured ground.
• Discharge printing, in which a bleaching agent is printed onto previously dyed fabrics to remove some or all of the colour.
Resist and discharge techniques were particularly fashionable in the 19th century, as were combination techniques in which indigo resist was used to create blue backgrounds prior to block-printing of other colours. Most modern industrialised printing uses direct printing techniques.

Read more...