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Check out the rest of our library for working with SMR premium vellum

Instructions for screenmaking with Vellum
When should you use vellum?
Printing on Vellum
Determining Correct Exposure for Vellum
Vellum Tips & Tricks

When should I use Vellum?

There is a tool for every job, and vellum is not the right tool for every screen printing job you might encounter. While vellum is a very inexpensive exposure positive for most jobs, and can beautifully handle roughly 80% of screen printing jobs, there are still those 20% of screen printing jobs performed by garment printers that are not a good candidate for vellum use.

Vellum has the following benefits as a screen exposure positive for screen printing:

  • Extremely low material cost - SMR Premium Vellum sheets cost as little as 1/15 the price of some of their film-type product counterparts.
  • Rapid delivery - Processing vellum sheets is as easy as printing the design in your computer printer. With traditional film, you will still need additional equipment to create and process the design on film. You will also spend roughly 10 - 20 additional minutes to expose - develop the film and you will have to wait for the film to dry.
  • Low overall cost - SMR Premium Vellum costs roughly 11 cents per 8.5" x 11" sheet when bought in packs of 500. Traditional film costs around $1 per sheet this size, requires additional equipment to process, requires roughly 50 cents worth of chemicals to process, and uses an average of 20 minutes total labor time to process. In all, a traditional film positive of this same size costs about $5.

As a paper-based product, vellum has the following shortcomings:

  • Shrinkage - Vellum can be shrunk slightly by the heat of laser processing, or distorted slightly by moisture in large solid areas printed by ink-jet printers.
  • Opacity - The opacity of a vellum positive can only be as good as the computer printer used to create the image carried by the vellum positive. See Printing with Vellum and  Vellum Tips & Tricks for tips on optimizing opacity.
  • Alignment - Vellum is usually printed by off-the-shelf computer printers, which may or may not be able to perfectly adhere to the dimensions of the originally intended design. In short, if your computer printer is not sufficiently accurate to output 2 separations that will line up, no matter what the printed media, you'll never get vellum separations that line up either. Any shrinkage or distortion factor caused by the printing process will not likely help alignment either. In contrast, film output devices are designed to be extremely accurate.

In short, Vellum is a great, inexpensive medium to use in screen making for:

  • Nearly all single color jobs.
  • Multi-color jobs where perfect alignment is not super-critical.
  • Screen meshes that do not require extreme exposure times. (Jobs using 20 mesh monofilament or dimensional printing buildups might be a problem)

Vellum will probably not be a good choice for:

  • 4-color process jobs or tight index color separations.
  • Jobs where exact measurements are critical - such as printing rulers or other measuring devices.
  • Jobs where extremely long exposure times are needed due to the thickness of the emulsion, if your printer cannot lay down a very dense image.

For jobs where vellum will not suffice, printers should use film positives or dry-film positives. Despite the much higher expense of using these mediums, film products offer:

  • Total light blocking in image areas.
  • No shrinkage factor.
  • Extremely accurate image placement and dimensional integrity.