There is always a debate on whether you should prime or not prime before placing your paint onto your furniture. Before I say yes or no to priming let's talk about a few things.
What is primer?
Primer is very similar to paint, but has a higher concentration of solids plus and adhesive binder in it. In short it seals the surface and provides a smooth, clean area for paint to adhere to. A good primer will block stains, and bleed through from happening.
When Should I prime?
If the surface is porous you need to prime. You can tell if a surface is porous if it absorbs water, oil, moisture or stains. If you choose not to prime this type of surface it will absorb your paint immediately.
If the surface is glossy you need to prime. You can tell a glossy surface just by looking at its sheen. For instance a high gloss paint, enamel or a shellac. If you choose to prime your paint will never stick no mater how many coats you place paint you use. Oh, and with a glossy surface you need to scuff sand to even have a primer stick to the surface.
If the surface is stained you need to prime. Stains can be formed by anything; water damage, candle smoke, smoke stains from cooking even smoking. A primer will act as a sealant so these stains will not bleed back through once you apply your paint.
If your piece has an order you need to prime. We have all experienced that beautiful piece of furniture that has been left to collect years of dust in a barn. You know the smell! You not only need to prime you will want to prime to help prevent this order from seeping back out and returning to haunt the furniture forever.
If your color change is drastic you need to prime. If you have a very dark piece of furniture and have chosen a light color. High saturated paint colors will show through lighter, less saturated colors. So save yourself the hassle of five coats or more and prime.
What about paint-primers?
The paint market is saturated with products that tell us they are an all in one paint and primer. These companies even go as far as to say one coat coverage. From experience, I have never been able to put just one coat of paint on, not even when I am painting walls. I have also found the smoothness, the color saturation and even the durability never last as long or feel as smooth if I haven't primed. So save yourself the time and aggravation and always prime before you paint.