many modern police cars use solid colors, primarily neutral tones such as white, black, and grey, often out of budgetary concerns; for example, the NYPD switched from baby blue to white in the late 1990s to save money on painting costs. Other colors, such as shades of blue, green, brown, tan, and red, are used by other agencies. In Canada, yellow was a common color used by municipal and regional police in Ontario until the 1980s; like the NYPD, most police services switched to white paint to save money. Today, most fleet markings on patrol vehicles are created from reflective vinyl with an adhesive backing that is applied in a peel-and-stick manner. Colors chosen to represent the agency's identity are typically chosen by the individual department, although, as noted above, some states have specific guidelines for color schemes and markings. Vinyl used to produce fleets markings comes in large rolls that are fed through a plotter (cutter) or large-format printer/cutter. The designs are created in specialized computer software and sent to the machines via a cable link for production. Once the design is cut into the vinyl, the excess vinyl on the sheet is removed in a process called "weeding". Finally, a paper pre-mask is applied to the top of the vinyl design to allow easy application of multiple letters and shapes at one time. Unmarked cars and ghost cars Unmarked police vehicles are common in most agencies in the United States and Canada. Most unmarked police cars are often the same models as marked fleet vehicles, and may be virtually identical to them aside from the lack of roof-mounted emergency lights; however, this depends on the agency, and some may use common civilian vehicle models to blend in with traffic. Many agencies also use "ghost cars" or "stealth cars", which are similar to unmarked cars, but have reflective graphics that are difficult to see unless illuminated by lights or viewed at certain angles. Ghost cars are often used for traffic enforcement, though they may also be used in jurisdictions where traditional unmarked cars are prohibited or have their enforcement capabilities limited, such as being unable to conduct traffic stops. Unmarked cars and ghost cars are controversial. Proponents argue they help deter illegal driving and keep undercover officers safe from detection, while detractors argue they unfairly focus on issuing tickets and make police less visible on patrol. There are also