Printing from screens prepared from paper, silk and others are one of the efficient printing techniques in the modern society. However, the printing technique poses some challenges to amateur printers. Thus, solutions to some of these problems in screen printing have been https://mytshirtkings.com/step-by-step-screen-printing-technique/ suggested. Most of the problems that are likely to occur in screen printing are:
(i) Bleeding of colours
(ii) Unequal gaps left between repeats
(iii) Irregular placement of screens or block/leaking screens and soiling of clothes
(iv) Formation of colour patches on the cloth
(v) Pin holes
i) Bleeding of colours may occur when the pigment (printing paste) used for the printing process is watery. If the pigment watery, during printing, at every registration, the pigment will bleed to the surrounding areas of the motifs thereby spoiling the printed cloth. To solve that problem, the printing paste must be thick enough so that at every registration, the pigment will stick to the fabric. Also at every registration, the under part of the screen must be cleaned.
ii) Unequal gaps left between repeats may also occur when the registration of the screen is not calculated. If the registration is not calculated, subsequent repeats of the design may not join thereby creating gaps in between the repeats. The problem could be solved by checking the repeats before printing starts. The repeats can be checked by using a coloured chalk to mark the various repeats on the fabric so that at every repeat one will know where to place the screen. Another solution is, a coloured strand could also be placed at the edge of the design widthwise so that the screen could be placed directly on the strand when the repeat is registered, the strand will be removed and the design will be printed.
iii) Irregular placement of screen may occur if the repeats are not checked. To solve it, the repeats have to be checked before the placement of the screen is done to register the print. Blocking /leakage of screens and soiling of cloth may also occur when the edges of the screens are not blocked. If the edges are not blocked, the printing paste will leak through the edges and soil the cloth. This is solved by using a masking tape to tape around the screen before printing starts.
iv) Formation of colour patches on the cloth may occur if the pigment is not distributed evenly on the screen. To solve this problem, enough pigment has to be used so that the paste will be evenly distributed to prevent this patchy effect. Also, the pulling of the squeegee must be well done.
v) Pinholes may occur as a result of any of these:
(1) The mesh used for the screen may contain some oils or gums and dirt in it. So if the development of the screen is done, because the silk was not washed to remove the dirt and other foreign matters in it, it will block the light from passing through so during washing, those portions would be washed off thereby creating pin-holes there. This could be solved by washing the mesh to remove every impurity before stretching it onto the screen.
(2) Pinholes may occur when there is under exposure of the screen during developing i.e. during the development of the screen, the due time for the screen to develop will not be sufficient or would not reach and the screen would be washed. If that is done, the chemicals would not develop enough on the screen so during washing most of it would be washed off, creating pinholes. This could be solved by allowing the screen to develop well, that is to reach the due time before it is washed.
(3) Coating of the screen can also create pinholes in the screen. This is so if the coating is not well done most especially when it is done once. After washing of the screen, there would be pinholes in the screen. This could be solved by coating the screen twice or thrice before developing is done.
These suggested solutions to the identified challenges are time-tested and born from the experiences of skilled screen printers. Therefore, printers using screens who confront the same or similar challenges can utilise these suggestions.