LESSON 10 ENLARGEMENT AND REDUCTION STRUCTURE 10.0
TOOLS REQUIRED FOR ENLARGEMENT AND REDUCTION 10.2.1 10.2.2
TECHNIQUE OF MANUAL ENLARGEMENT
TECHNIQUE OF MANUAL REDUCTION
ASSIGNMENTS 10.5.1 10.5.2
CLASS ASSIGNMENTS HOME ASSIGNMENTS
POSSIBLE ANSWERS TO SELF-CHECK QUESTIONS
REFERENCES AND SUGGESTED FURTHER READING
10. ENLARGEMENT AND REDUCTION OF DESIGNS The size of a design motif is of significant importance in textile designing. To ascertain the size of design to be placed on the fabric, a designer should be aware of the concept of enlargement and reduction before taking any designing project. The first lesson in this unit will therefore deal with this important aspect. The next two lessons will present a study of various types of designs, their placements, and repeat patterns and all over designs for ornamentation on fabrics.
10.0 Objectives After going through this lesson you will be able to: â€˘
Recognize the tools and equipment available for enlargement and reduction
Perform the process of manual enlargement and reduction
10.1 Introduction Enlargement and reduction represent two of the very basic designing treatments given to a motif or a design as a whole. Textile designers make use of these techniques quite often, particularly when designing prints, for example, for screen printing or block printing. To give a very simple example of what we are going to study in Lesson10, let us examine Fig. 10.1. It will be observed that in this composition, the rectangle is used in two different sizes and orientations. The bigger rectangle has been scaled down (reduced) to half its size. Also the rectangles have different orientations. This lesson will describe the tools and techniques used for enlargement and reduction of design.
Fig. 10.1 Composition of rectangles
10.2 Tools Required for Enlargement and Reduction 10.2.1 Epidiascope An epidiascope is an instrument (Fig. 10.2) used generally for enlargement of design. The design to be enlarged is placed on the flat glass top of the instrument called the projection plate. The amount of enlargement is adjustable. The enlarged image is projected on the screen or on a white wall in front of the instrument. An epidiascope helps in magnifying the design to very large sizes. Once the desired size is achieved, a sheet is placed on the screen and the outline of the design can be traced very easily. The epidiascopes are available in various capacities.
Fig. 10.2 An Epidiascope
10.2.2 Photocopier We are all well aware of the photocopier which is more popularly known as the xeroxing machine or the xerox machine. In fact Xerox is the name of the company which makes the photocopiers. It has been a pioneer in this field and earned a good name for itself so much so that a photocopy is called a xerox and is thus known by the name of the company itself. A Photocopier can also do enlargement and reduction, copying on both sides of the sheet of paper, and also copying in colour. The photocopier has become a very essential designing tool. It has made the time-consuming task of manual enlargement and reduction much easier and quicker. Now, it just takes seconds to reduce the size of a design say from 10” X 8” to 5” X 4”.
Self-check Questions 1. What are the various functions a photocopier can perform? 2. Why does a designer require a photocopier?
10.3 Technique of Manual Enlargement A motif or a design can also be enlarged by the desired amount, say doubled in size or made four times; etc. by drawing it free hand. This is a possible method, but in this method the exact proportions of the design may not be maintained. To enlarge a design to a very specific size and with great accuracy, this method will not be very dependable. For exact and precise enlargement the following method is recommended.
Step 1: Enclose the design to be enlarged (Fig. 10.3) in a box. (Fig. 10.4) The box should be made in such a way that the lines of the box touch the furthest points of the design. Thus you get a box exactly the size of the design to be enlarged.
Fig. 10.3 The design
Fig. 10.4 Design enclosed in a box
Step 2: Measure the length and breadth of the box. Now divide this with the number of parts into which the design is to be divided. For example: If the length of the design box measures 3.5 inches, and say we want 7 divisions of the design length then we divide 3.5 inches by 7. This gives us 0.5 inch. Thus mark points at a distance of 0.5 inch each on the left and right line of the design box. So we get 7 equal divisions. Name the points as a, b, c, etc. and so on, as in Fig. 10.5.
Fig. 10.5 Divided image 2
Similarly, measure the breadth of the design and divide it into a convenient number of divisions. Suppose the breadth is 2.5 inches, and we decide to divide into 5 parts then we divide 2.5 inches by 5 which gives us 0.5”. So we mark points on the upper and lower sides of the box and number them as 1, 2, 3 etc. As far as possible, the divisor should give us a whole number so that marking the points becomes convenient. Step 3: Now suppose we want to double the size of the design. To achieve this make a new box of the size which is double the size of the original box measured in Step 2. For example, the size of the box was 3.5”x 2.5’’. So now the box size will be 7’’ x 5’’. If the design had to be thrice its original size then the new box size would have been 10.5’’ X 7.5’’.
Fig. 10.6 Enlarged grid
Now, once again we have to form the grid in the new big box. For this we have to maintain the same numbers of divisions as were made in the small box. We had 7 divisions, each of 0.5’’ in the small box. So we again make 7 divisions in the length of the big box, but now the size of each division would be double the size of each division in the original box. So we get each division as 1’’. Similarly the size of each division breadth wise in the big box would be double the size of each division in the small box. Now number the points in the same fashion as in the small box. This is shown in Fig. 10.6. Step 4: Once the new box is ready with the grid, start drawing from the first grid. The design part which is in the first grid of the small box has to be made in the corresponding first grid of the big box. We continue to draw in the big box exactly the corresponding part which is in the small box. (See Fig. 10.7).
Fig. 10.7 Redraw design on the enlarged grid
Step 5: Continue drawing the design as described and the enlarged design will be obtained which is exactly double the original design, as is shown in Fig. 10.8.
Fig. 10.8 Enlarged design
Self-check Questions 3. State True/False for the following statements: i)
If a design is scaled down from 4’’ to 2’’, it has been enlarged.
If a design has been made from 5’’ to 10’’, then it has been enlarged.
Activity 1. Copy a design and enlarge to four times its size.
10.4 Technique of Manual Reduction A motif or a design can be reduced to the desired size, for example to half or one fourth the original size etc. One has to follow the same procedure as for enlargement
with the difference that the second box, in which the final design, is to be made is smaller in case of reduction where as in enlargement it was bigger than the original design box. We select a design and follow the steps given below: Step1: Enclose the design to be reduced in a box. The box should be made in such a way that the lines of the box touch the furthest points of the design (Fig. 10.9a). Step2: Measure the length and breadth of the box. Now divide this by the number of parts into which the design is to be divided. For example: Here the size of the motif taken is 7’’ x 5’’. The length of the design box measures 6 inches, and say we want 6 divisions of the design then we get 1’’ division each (6’’/6 =1’’). Thus mark points at a distance of 1’’ each on the left and right lines of the design box. So we get 6 equal divisions. Names each point a, b, c, etc. Similarly, measure the breadth of the design and divide it into a convenient number of divisions. The breadth is 5 inches, and we decide to divide into 5 parts then we divide 5 inches by 5 which gives us 1 inch. So we mark points on either side of the box and number them as 1, 2, 3 and so on as shown in Fig. 10.9b. While deciding upon the number of divisions to be made, the divisor should give us a whole number so that marking the points becomes convenient and accuracy is maintained.
Fig. 10.9a Enclosed design
Fig. 10.9b Design grid
Step 3: Now decide upon the scale to which the design has to be reduced. Suppose we want to shrink the design to half its original size. To achieve this make a new box of the size which is half the size of the original box. Since the original size of the box is 7”x 5’’, now the box size will be half of that i.e. 3.5’’x 2.5’’.
Once again we have to form the grid in the new small box. For this we have to maintain the same number of divisions made in the original box. We had 7 divisions, each division of 1’’ in the length of the small box. So we again make 7 divisions in the length of the small box, but now each division would be half the size of each division in the original box. So we get each division as 0.5’’. Similarly the size of each division in the breadth of the small box would be half the size of each division in the original box, i.e. 0.5”. Now name or number the points in the same fashion as in the big box (Fig. 10.9b). Thus you get a box exactly the size of the design to be reduced. (Fig. 10.10). Fig. 10.10 Reduced grid
Step4: Once the new box is ready with the grid, start drawing from the first grid. The design part which is in the first grid of the big box has to be made in the corresponding first grid of the small box (Fig. 10.11a). With the help of the labeling done, carefully identify the corresponding grid and keep drawing the design. The grid lines will guide you to maintain the outline of the design. We continue to draw in the small box exactly the matching part which is in the big box till the whole design is complete. (Fig. 10.11b).
Fig. 10.11a Drawing on the reduced grid
Fig. 10.11b Reduced image
Self-check Questions 4. Fill in the blanks:
A______________ can also be used to produce print on the reverse side.
When reducing a design the ________ (first/ last) step is to make a box around the design.
iii) The number of divisions made in the new box will be the ___________ (same/ different) as the number of divisions in the old box. iv) When enlarging, the size of each division of the grid is __________ (bigger/ smaller).
Activity 2. Reduce a 15 inches x 28 inches design/motif to 5 inches x 7 inches.
10.5 Assignments 10.5.1 Class assignments i)
Enlarge a 4 cm square design/motif to 4 inch square.
10.5.2 Home assignments i) Visit a Photocopying shop and get your design enlarged and also reduced.
10.6 Summing Up Enlargement and reduction are very important techniques to be used in drawing and designing. The purpose of enlargement of a design is to expand or make the size bigger than the original one, and the purpose of reduction is to reduce the design size. The usual and easiest and most commonly followed way for both, is drawing a square grid superimposed on the design with the help of a pencil and a ruler by hand. However nowadays equipment like an Epidiascope , a Photocopier or a Computer Software ‘Corel Draw’ are available which have made it possible to do enlargement and reduction of design size very quickly and accurately.
10.7 Possible Answers to Self-check Questions 1. A Photocopier can •
produce desired number of copies of a document or a design
copy in colour
copy on both sides of the sheet of paper 9
do enlargement and reduction.
2. A designer requires a photocopier to get as many photocopies of the design as he likes in the required enlarged or reduced size. 3. i) False ii)True 4. Fill in the blanks: •
10.8 Terminal Questions 1. Explain the process of reduction. How will you reduce a 10’’X 8’’ motif to half its original size? 2. Give brief descriptions of epidiascope and photocopier. 3. What do you understand by the terms enlargement and reduction? Draw a composition of basic shapes using circle, square, triangle, rectangle etc., showing both the techniques i.e. enlargement and reduction.
10.9 References and Suggested Further Reading 1. Anonymous. 1979. Craft and Hobbies: A step by step guide to creative skills. Readers Digest Association, Inc., New York. 2. Anonymous. 2006. A Complete Guide to Drawing and Painting. Quantum Publishing Ltd., London.
10.10 Glossary 1. Enlargement
Increasing the size
Decreasing the size
An instrument for projecting the images of opaque objects or transparencies on a screen
A machine that uses a form of photographic process to copies of documents or illustrations.
Published on Mar 5, 2012
Published on Mar 5, 2012
10.6 S UMMING U P 10.8 T ERMINAL Q UESTIONS 10.3 T ECHNIQUE OF M ANUAL E NLARGEMENT 10.9 R EFERENCES AND S UGGESTED F URTHER R EADING 10.4 T...