What is Textile printing?
The word “printing” is derived from the Latin word meaning “pressing” and implies the application of “pressure”. Textile printing is the process of applying color to the fabric in definite patterns or designs. Textile printing is related to dyeing, whereas in dyeing, the whole fabric is uniformly covered with one color. In printing, one or more colors are applied to the fabric in certain parts only, and in sharply defined patterns. Printing is therefore called as localized dyeing.
Common Printing Faults or Defects in Fabric:
Defects that occur in the fabric during the operation of printing are called printing defects. Each printing method has its own unique printing limitations and problems, which appear in some cases as printing defects. The appearance and magnitude of these defects are dependent on the printing paste, the printing parameters and the printed patterns. Defects can be so small that they have no effect on the function of the patterns.
Printing defects may occur due to many reasons such as the following:
- The printing procedure did not take place properly
- The fabric was not prepared properly before printing
- The fabric had defects prior to printing
The common defects which occurred on fabric in printing process are given below:
- Flushing / Wicking
- Bleeding
- Misfits
- Stick-ins
- Double printing
- Scrimps
- Pattern bending
- Unwanted pigment marking on Fabric
- Mottled
- Crack or Miss alignment in transfer printed fabric
- Doctor mark / streak
- Printing machine stop
- Color out
- Uneven printing
- Frame marks
The causes and remedies of these common printing defects in fabric are enlisted below:
1. Flushing / Wicking:
Caused due to Low viscosity of print paste.
It occurs when the printed area bleeds out into the unprinted area. The result is a haloing or shadowing effect around the outline of the pattern design.
2. Bleeding:
Bleeding defects occurs in fabric when printing paste that has already been applied bleeds into a subsequent paste or coating this is applied. Also known as smearing, bleeding is typically caused by the initial ink drying too slowly, and can be resolved by reducing the ink’s viscosity or by using a faster solvent. The causes for this type of defect can be as follows –
- The print paste has low viscosity
- The concentration of the dyestuff in the print paste is too high
- It is major defect as it happens throughout the fabric unless the viscosity is corrected.
3. Misfits:
A misfit is a print defect caused by improper alignment of the screens. Also known as out of registration, misfits leave unprinted areas in the design.
For example, a green leaf may overlap its black outline or print over another color.
4. Stick-ins:
A stick-in occurs when a small fiber or piece of lint gets stuck in the screen opening.
The result is a small unprinted circle in the design. A stick-in is very difficult to see and often goes unnoticed during a long run.
5. Double printing:
Double printing defect occurs in the fabric when the design to be printed are not in the correct position of where they should be. The causes for this type of defect can be as follows –
- The design was not correct
- The print design was not able to adhere to the fabric
6. Scrimps:
A scrimp defect occurs when the fabric creases underneath one of the screens during the printing process.
The pattern is then printed on top of the crease, leaving a large unprinted area when the fabric returns to its relaxed state.
7. Pattern bending:
Defect created by the print head’s movement over the substrate.
Use of scanning print head or a print head that moves back and forth across the substrate in straight line placing drops of ink at precise locations along the line.
If the head is not properly aligned, or if the substrate advances unevenly, the result is a slight horizontal band or line of unprinted area.
8. Unwanted pigment marking on fabric:
Caused due to screen has holes in it that should have been covered. This could be because of ageing of the screen and eventual damage or just improper exposure to light.
9. Mottled:
Color applied unevenly during printing.
10. Crack or Miss alignment in transfer printed fabric:
Incomplete transfer of design from paper to fabric on transfer printing due to removal of transfer of paper while the fabric was still hot.
11. Doctor mark / streak:
Doctor mark defect occurs in the fabric when parallel lines appear on the fabric, vertical to the print on the fabric. It is called so because it is caused by damaged or improperly set doctor blade in the printing machine. A doctor blade is a metal knife that cleans or scrapes the excess dye from engraved printing rollers, leaving dye paste only in the valleys of engraved areas. The causes for this type of defect can be as follows –
- The print paste has low viscosity
- The concentration of the dyestuff in the print paste is too high
12. Printing machine stop:
As a result of printing machine stop the dye sometimes is smudged along the width of the fabric.
13. Color out:
The result of color running low in reservoir on printing machine.
14. Uneven printing:
Uneven printing defect occurs in the fabric when the tone of the color of design has gaps through the fabric. The causes for this type of defect can be as follows –
- The screen was not prepared properly
- The squeegee was used with uneven pressure
15. Frame marks:
Frame Marks defect occurs in the fabric when the frame used to print on the fabric leaves a mark on the print. The cause for this type of defect can be as follows –
- The frame was not installed properly in the machine
You may also like:
- Working Process Flow Chart of Textile Printing Industry
- Different Types of Textile Printing Techniques
- Application of 3D Printing in Textile and Apparel Industry
- All Over Printing Techniques
- Digital Textile Printing Technology: Evolution, Progression and Techniques
- Burning Out Print Techniques
- Types of Fashion Prints on Fabric
- Different Types of T-shirts with Lots of Graphics
- Leather Printing Techniques Step by Step
- Process Flow Chart of Printing Screen Preparation
- Denim Printing Techniques
- Latest Developments in Textile Printing Techniques
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
A wonderful learning