Shears are basically heavy duty scissors. Every workshop needs them. They are good for cutting everything tough materials like fabric, leather, cardboard, EVA foam and plastic.
Shears are different from scissors in that they are specifically designed for heavier applications. Most of them have micro-serrations along the blade edges that makes them unsuitable for fine work, like cloth and finished foam edges. We use them for cutting patterns from paper and poster board as well as cutting foam sheets down to manageable sizes.
In our workshop we have several sets of the shears pictured because their handles are designed to be ambidextrous – meaning you can use them with either hand. The long handles makes it easier to cut thicker materials with ease. They are also titanium clad – making them tough enough to not dull quickly while cutting 10mm EVA foam, cardboard or poster board.
While these shears are good, there are many excellent examples out there.
Below are some links to good shears available at different locations.
The ones we use at Harbor Freight ($9.99)
Crescent Wiss at Amazon.com (normally $27.01, but $15.99 right now)
Kobalt (a 2 pack) at Lowes ($15.98)