Grayscale is a range of shades of black on a spectrum from 1 to 100. Light gray is in the lower spectrum and darker grays are in the higher spectrum. While 100% black images and text will produce crisp line art and is the norm for letterpress, sometimes you may want to print something where you want to see all the details and subtleties of the shading.
If you are trying to print a photographic image, it’s best to choose one that has areas that provide high contrast between light and dark, that is, the photo has details that are both darker gray in the upper ranges (70 to 100% of black) and lighter gray in the lower ranges (5% to 35% of black). This contrast will give the most depth and interest to the photo. If your photo has mostly shades of black in a similar range (30 – 60% of black), it will look muddy to the eye because it’s harder to discern the shading without a lack of contrast. Experimenting with the image in Photoshop by changing levels of black or adding brightness and contrast can help some with this.
If you are printing a scanned image, where you want to keep the tonal imagery, you can send the file as grayscale and we’ll apply a line screen to it. Your image will be a large shape with the tones created as little dots on the surface of the plate. The films are very sensitive and will capture shades of black down to 5%. So if your background has some color, it may be picked up by the film and show on your plate.
Halftones and grayscale images can be challenging to print with relief plates on the commonly used uncoated papers of letterpress. Call us to discuss your particular image and the results you want to achieve.