This is a copy of an article by E A D Hutchings in the 1960 volume of Print In Britain: this article is about using a scaled-down plan to create the best possible printing surface to use on much larger machines. If you are a ‘small’ letterpress printer today this is essentially describing some parts of your set-up: great equipment, low-volume work and an emphasis on quality. I’ve presented it here to give you some insight in to what the ideal set-up for a small printing office was in the 1960s.
Pre-press techniques are now an accepted practice in all the larger, and many of the smaller firms in this country; but what of those small firms who have not yet followed this trend? It is the small firms who form the bulk of the industry, yet a very large number of these have no pre-press organization within their works. This slowness to adopt new techniques often springs from a mistaken idea that pre-press means a large capital outlay for specialist equipment, that this in turn requires re-equipping the machine department in order to obtain the maximum value from the precision materials and equipment which have been installed, and that such large scale re-organization will require the firm to branch out into new fields of printing and completely change in character in order to keep all this new equipment in production.
This is a completely false assumption. Basically, pre-press and precision techniques are methods of reducing or eliminating waste: waste of production time on the machine, of consumables and materials, and of the capacity of machines.
The average small firm equipped with three or four automatic platens, two small automatic cylinder machines and a double demy Wharfedale or similar machine and engaged in the normal run of local jobbing printing supplemented with work from one or two larger customers, can profitably install and run a small pre-press section with very little capital outlay. Initially this is a matter of re-organization of existing equipment and manpower rather than of capital outlay. Re-organization on the lines suggested in this article should show a saving in materials waste as well as giving increased production.
The first consideration when introducing a pre-press section into a works for the first time is one of staffing, for it is important that the work carried out in this section is controlled by one man. Many small firms employ a working foreman in the machine room. He is the senior machine printer, and in addition to working a production machine himself, he is required to issue work to the other machines, pass work for position and for running on, ensure that there are sufficient supplies of cleaning materials and lubricating oils, and to issue and keep in order the stores of ink, solvents, driers etc. This means that he will often be required to switch off the machine on which he is working while he carries out these other duties. This results in a complete waste of production time on that machine.
When organizing a pre-press section for the first time it is suggested that this person is the one who should run the pre-press section and that his place on the production machine should be taken by a machine printer who is solely concerned with the production of printed work. He can then continue to devote himself to the day-to-day running of the machine department while the remainder of his time is spent in preparing work for the machines. It is of vital importance that the pre-press section is staffed by someone who is both keen and sympathetic to new ideas and imbued with ‘precision-mindedness’.
Siting the section
Where possible the pre-press section should be sited between the composing and machine departments so that formes, spacing material etc, can pass freely through from the composing room and on to the machines. A great deal will, of course, depend on the building in which the firm is housed, but when possible the best position for a small section similar to that envisaged will be at that end of the machine department which is nearest to the composing room.
Equipping the pre-press section
In addition to the amount of capital outlay intended, the size of the firm and the nature of the work which is normally carried out are the deciding factors when considering the type and amount of equipment which is to be installed in the first instance. The cost of this can range from tens of pounds up to thousands, but a small firm should be able to equip and work an efficient section for a total outlay of less than £100 providing that an efficient proofing-press and a reasonable amount of precision spacing materials and metal plate mounting base are already installed.
A sufficient area must be allocated to the section to install shelving to carry a week’s supply of paper stocks, an ink cupboard, a cupboard or cupboards for consumable materials and one for roller storage. A precision proofing-press and an imposing surface together with a stand for making mechanical overlays and a table or desk with a top large enough to carry the largest sheet which can be printed on the production machines form the remaining standing equipment.
The imposing surface takes the place of a precision register table, and the desk is in place of a revisor and line up table which is the equipment which would be installed if a greater capital outlay is intended. A more efficient alternative to an ordinary table, which would cost only a little more, is a glass topped light table. This should have a 1⁄4″ opaque ground glass top, illuminated from below by one or two low power fluorescent tubes. Such a table could easily be constructed by a local woodwork firm to specification at little cost and its use will considerably simplify the registration of colour formes, and checking the perfecting of sheets. An 18″ steel square and a 3′ steel rule or straight edge will also be required for use with this equipment.
A great deal of the shelving, cupboards and other standing equipment can be constructed from metal angle section. Two forme racks will also be required in this section, one for formes waiting to go on machine and the other for formes waiting to be checked. In a small firm it will often be useful to have the platen and cylinder dressing sheets stored here as well. This stock should be cut to size for the individual machines and kept separate according to the machine size and the type of stock so that packings of differing characteristics can be quickly chosen for varying classes of work.
Whatever the type of mechanical overlay it is decided to install the overlay bench should include shelves for storing a supply of overlay stock and materials and a range of hard stock in varying thicknesses for underlaying and bringing to type height any wood mounted plates. The top of the cabinet should be large enough to carry any apparatus which may be necessary to process the overlay pull, and to take a type high plate gauge.
The four types of mechanical overlay which are in common use at the present time are the 3M, Primaton, Chalk Relief and Lacolite systems. The first two are the more expensive to install initially, 3M requiring a special heater to fuse the overlay pull while the Primaton method requires some source of direct heat to process the pull also. Of the remaining two methods the chalk relief overlay is probably the more suited for pre-press use, although the Lacolite has some advantage in that it can be made on the press and run immediately.
The proofing-press can be any one of the many excellent precision machines which are now available. It need be no bigger than the size of the largest production machine and, in many cases, need not be as big. If it is intended to purchase a new machine it is as well to consider the merits of some of the powered presses. These machines are capable of printing small runs of up to about 200 with greater economy than on a production machine of conventional type in many cases. A firm who retains an old Wharfedale press for a lot of short run poster work, for example, will possibly find that the purchase of a press of this type will give them a production machine for this type of work in addition to its use for pre-press, and thus enable them to dispose of the old machine and use the space it occupied to better purpose.
A section organized on the lines suggested, and with this minimum of equipment, will be capable of cutting down makeready time on the production machines by quite a reasonable figure. Formes will be taken from the composing room and locked in position in the machine chase. Accuracy and register can both be checked, using the straight edge and set square and also by using sheets of thin acetate. These can be obtained squared with a grid, or plain. Many small automatic machines now have register devices which use these sheets. These devices are pegged on the machine chase, and similar devices can be made and existing machine chases adapted to take such a register device by any competent engineer at quite a low cost. Where work in two or more colours is being run these devices can save a tremendous amount of time on the machine as each forme can be accurately registered in a second machine chase while the first colour is being run.
All plates should be sent to this section before they are placed in the forme; it is suggested that plates should be ordered flat, or unmounted and that metal mounts should be used throughout. The cheapest method of mounting on metal when no precision mounts are already available, will be found to be the wood-filled quad. These can be obtained in various heights for both original and duplicate plates. The plate and mount will be levelled in the pre-press section and overlays or interlays made as they are required.
Ink and colour matching
The ink cupboard should have a top which will carry an ink mixing slab, weighing equipment and palette knives, wash-up materials etc. Accuracy and economy are best served by having one person responsible for the original matching of proofs and for the subsequent batch mixing for the run itself. Both of these tasks are best carried out within the pre-press section. In the course of time a record book of mixings should be built up and retained in this section. This record is best retained in loose leaf form with index tabs to separate each section into dominant hues ; tints, shades and greyed colours will each fall within their own section. A pull should be taken on a standard colour bar and the details of the mixing together with the customer’s name and the date should also be shown on this sheet.
This record will not only make it easy to match accurately a colour for reprint work but will also greatly assist the matching of other colours. If the record is consulted a colour will often be found which, if not an exact match, will often be close enough to give only slight alteration to the existing formula. This record will also serve a useful purpose when a customer requires colour work to be done.
Such a record book can be started initially by taking a print of all the colours normally carried in stock, together with a series of two or three tints, shades and greyed colours of each of these colours. These colours alone will often be chosen for work and will give a good indication of the range from which a mix can quickly be made. An additional advantage is that any weakness in the range of colours normally carried will be readily exposed and the range of inks carried in stock can eventually be amended.
Very little special equipment is required for ink mixing; a mixing slab, ink knives and a simple set of weights and scales are the basic requirements. A small mixing mill is a valuable addition to this equipment when the mixing of colours is an almost daily, or a weekly occurrence. A simple mill consisting of a bowl and stand and fitted with a hand operated mixing paddle is adequate for quantities of up to several pounds weight. (Details of all ink mixing equipment are to be found in the BFMP ‘Precision aids for Printers’ booklets.)
The ink slab on which the colour will be mixed in the first matching is best made from 1⁄4″ plate glass. This should be painted white on the underside and secured to the top of the ink mixing cabinet at the corners by metal corners of the type used for some picture frames. Opaque white glass can also be used for the slab when this is obtainable locally and this will often prove more satisfactory than plain glass.
Colour matching and mixing requires good natural lighting if accuracy is to be maintained and it is as well to consider the merits of a special colour matching lighting unit for this section. An excellent unit of this type is available which can be installed for less than £30 all in.
So far only the pre-press duties which are to be undertaken by this section have been considered but there are many firms where these duties alone will not be sufficient to keep a man employed for the whole time, even when combined with the day-to-day running of the machine room. In these cases it is suggested that the duties of this section should be extended to include the control of the machine room stores- This will include such items as the lubricants and consumable materials such as cleaning rags, paraffin, etc, in addition to the ink stores. In some cases the control of cut stocks prior to printing can also be considered.
Paper is the material which comprises the bulk of the finished product and which forms the single greatest element of materials cost. To reduce the wastage of paper to a minimum and to reduce trouble on machine and in the bindery it is of the utmost importance that the paper which goes on the machine is stable and correctly matured.
An analysis of troubles on machine will reveal that those caused wholly or in part by immature paper can exceed 50 per cent of all stoppages. Under certain conditions paper with an uneven moisture content or a moisture content out of balance with that prevailing in the machine room can cause or be a contributory factor in such faults as slurring, creasing, register faults, picking, plucking, chalking, poor drying of ink, and set-off. When paper has too little moisture content compared with the atmosphere in the machine room it can also become charged with static — a condition which, even in mild form, can cause untold delay on the machine and in the subsequent bindery operations, and can cause a high spoilage rate.
Ideally paper should be stored in a warehouse with an atmospheric temperature and humidity identical with that in the machine room (65° F and 65 per cent relative humidity are ideal conditions). This requirement of equal and balanced atmospheric conditions for both paper storage and machining is more easily achieved in open plan works where store and machines are virtually in the same room and only separated by a partition or gangway. Unfortunately, in many small works the paper is often stored in another part of the building, if indeed it is not in a completely separate building, often with totally inadequate heating.
Where paper cannot be stored in conditions which are consistent with those in the machine department a supply of the stock, sufficient for a normal week’s work, should be retained in the racks put up in the pre-press section and stock for machine taken from this supply, which should be renewed daily so that all paper will have matured in the machine room for a week before being put on the machine.
It will often be possible to have a great deal of this stock already cut to size for work before it is stored, so that the section is able to issue the cut stock to the machine printer when the jobs are allocated.
Many firms do not have a separate ink store, the ink that is carried being stored in a cupboard in the machine room. These are then taken and returned by each machine printer often with no supervision whatsoever. This lack of system often leads to a great deal of waste, several tins of the same ink being opened and returned to store half empty, tins of new stock being used before older stocks of the same ink have been used, and partly used tins of ink being kept on the machine instead of being retained in store. A look round many a machine room will often reveal half empty tins of ink under machine benches, often in a state when they are no longer fit to use, and other tins in store with a thick skin over them which must be taken off and thrown away before the ink left in the tins can be used. The prevention of this waste alone could show a saving of many pounds in the course of a year.
When there is no proper ink store, ink, together with ink solvents and driers, etc, should be stored in the pre-press section, kept separate by colours and types. This ink should be issued with the job and the surplus returned when the work is completed. Record cards should be kept showing the job against which ink, solvents and driers, etc, are issued; the minimum stock to be kept in hand, and in larger stores, the location of each particular item should also be shown.
Ink returned to store should be inspected to make sure that the tin is clean, particularly round the top so that the lid is easy to remove and replace. The surface of the ink remaining in the tin should be flat and level. It is a good idea to pour about a quarter of an inch of water on the top of the ink before replacing it in the store. This will prevent a skin forming on top.
Storing the ink in this way under supervision is also a safeguard against the improper use of driers or reducers which can often lead to the spoiling of work.
Tins of ink are marked with the date of manufacture but when reasonably large stocks are carried it is advisable to introduce an additional code of marking so that stock purchased at different times can be quickly seen. A rubber stamp or simple label stuck on the lid or on the back of the tin will usually be sufficient and will act as a further check against new stock being used while older stocks of the same ink remain in the back of the cupboard.
Waste can again be reduced or eliminated by having all consumable items stored in this section and issued under proper supervision. Under this heading will come such items as anti-set-off spray powder and spray fluid, cleaning cloths, machine oil, paraffin, makeready tissue, paste, etc. With items such as cleaning cloths a simple system of exchanging an equal number of clean cloths for dirty cloths returned will usually prove sufficient. The main value of retaining the other items enumerated is in
14 ensuring that a sufficient stock is always on hand to meet all requirements. Sending the junior apprentice round the corner to get a gallon of paraffin seems of little importance perhaps but it all adds up to a substantial loss of production in the course of a year when running out of paraffin is a comparatively regular occurrence!
Other items which the pre-press section should be able to check and maintain is equipment such as mechanical quoins and numbering boxes. A stock of good mechanical quoins represents a capital outlay which cannot be ignored, and simple and robust as their construction invariably is they still require a certain amount of maintenance if they are to give useful service for the maximum length of time. Each quoin will find its way into the pre-press section in the normal course of events as formes are passed from the composing room and passed on after checking on to the machines. A touch of oil or grease on the working parts and a clean up of any dried ink, etc, on each quoin as a periodic service will take up little time at this stage and will prolong the useful life of these items almost indefinitely.
Numbering boxes, if they are to give trouble-free working, require to be kept clean and slightly oiled. This task again is one which can best be carried out within a section such as the one envisaged. Formes should be made up in the composing room with accurately cut blocks, the exact size of the numbering box, and the box itself is not put in the forme until this is sent to the pre-press section. As formes are returned from the machine the boxes are removed and the blank blocks replaced. The boxes are then cleaned and a spot of light oil introduced into the mechanism before they are replaced in store. When stored the box is best kept in a small tin, lined with felt which is lightly oiled.
Machine rollers are another item which are best retained in this section when not in use on the machine. Storing them centrally in this way will enable a check to be made on their condition and a periodic examination and attention which rollers in store require to be given. Rollers being returned after recovering will be checked for accurate centring of the stock and correct diameters. This examination can easily be carried out using two blocks of the correct size on the imposing surface or similar flat surface. If a pair of blocks are made accurately for each size of roller carried there will be no need to use a pair of calipers for measuring the diameters.
To sum up, reorganization on the lines mentioned will result in a central inspection station where work can be checked, alterations or corrections made, and a great deal of the preliminary work carried out before the job goes on machine. It will provide a central store for all machine accessories and materials and a check and maintenance unit for the many precision pieces of equipment which printing to-day demands.