Preparation

1. Choice of ink

When choosing right ink for silkscreen printing on acrylic, high-gloss, scratch-resistant ink is what we want. Don't use matte ink when printing on the surface, because it is not resistant to friction. The color is duller than that of glossy ink. It's not bright enough.

2. Choice of screen

It is good to choose high-resolution photosensitive adhesive and high-tension, low-stretching screen. The cost is a bit higher, but the screen is clear, and the edges of the patterns are neat. It also ensures the accuracy of the position when multi-color overprinting.

3. Ink mixing

Ink mixing is important in silkscreen printing on acrylic. It decides whether the pattern is bright or dim, whether there is chromatic aberration. This step is usually finished by experienced colorist.

4. Cleaning before silkscreen printing

Cleaning is necessary before silkscreen printing. There are not too many dust-free workshops. Dust and debris will fall on surface of acrylic sheets after being placed for a long time. If there is no cleaning at first, patterns will be incomplete, resulting in defective products.

5. Alignment

You must focus and take care during alignment. There is no complicated skill involved, but it's not easy. If the alignment is not accurate, the pattern will be offset. It's bad, especially for small products like acrylic photo frames.

Process Improvement

1. A basic thing for perfect pattern reproduction is that good quality of transparent positive films. The edges of printed dots should be particularly neat and opaque. The color separation film and ink should use the printing machine with same color standard.

2. Put positive film on acrylic sheet. After exposure, place the stretched screen on the positive film parallel to the image axis. If moire appears, rotate the screen left or right until it disappears. The area prone to moire is in the direction of the screen wire and at the intersection of the screen.

3. For four-color printing, you should use the same size and stable aluminum screen frame. The stretched screen should be the same type and model. Dyed screens can help eliminate moire. The tension of screen should be uniform and consistent, and the tension of the 4 screens for four-color printing should be the same.

4. A well-ground scraper is essential for high-quality printing. The scraper grinder is also important. The Shore hardness of the blade is about 70. The scraper should be set at an angle of 75 degrees. If the angle of the scraper is adjusted too flat, the pattern may be blurred. If the angle is adjusted too steeply, the pattern has high risk of deformation.

5. Ink reclaiming blade should not be installed too low. Otherwise, the stencil will be filled with excessive ink. The printed product will be easily blurred and smudged.

6. The finer the screen, the more intense the color of ink. The Shore hardness of squeegee should be 75. In order to prevent the ink from getting dirty when the colors are overprinted, the silkscreen printing is recommended to be in the color sequence of cyan, magenta, yellow, and black.