How to pick out and buy a screen
TRUST ME.... it sucks when you use the wrong screen... almost as much as it sucks when you find out your stencil is shitty.
So, here are some things to evaluate before you buy a screen along with their pro's and con's
Wood frames are less expensive, yet are heavier and have the potential to warp if not properly cared for. For some, the weight of the screen is appealing while others dislike it. If you are not going to be doing commercial printing, or are just going to be printing occasionally, then a wood screen is a good inexpensive option.
The benefit of an aluminum frame is its light weight and longevity. With both wood and aluminum frames you can re-stretch the screen if it ever becomes damaged or needs to be replaced, though, the aluminum frame will hold up over time much better. If you are going to take printing more seriously (i.e. doing large editions, commercial work, etc) get aluminum. You do not have to tape up the edges of an aluminum frame, but for the sake of just being safe, you should tape around the edges where the mesh is glued on.
Mesh Count is how many threads cross per square inch
Why does mesh count matter? Well, the higher the mesh count, the higher amount of detail you can achieve. This is especially important if you are going to print some CMYK shit. If your dot pattern is smaller then then the space between the threads, then it is NOT going to print well...... Likewise, if you are printing on fabric, fabric screen printing ink has much larger pigments then regular screen printing ink, and doesn't actually FIT through some of the higher mesh counts.
Standard mesh sizes and their benefits as follows:
40-86- really only use screens of this mesh count if you are printing with glitter or something wacky like that.
110- good for getting lots of ink on the paper/fabric. Think bold designs and lettering when using this size mesh. Make sure your ink isn't too runny!
156- you can still get some thick ink out of this screen, but you've got a bit more flexibility with adding finer detail. Your ink can also be a littler looser when using this count.
200/230- you've got your self a fancy screen! You can print pretty tiny detail with this mesh, and its good for CMYK halftone patterns. Your ink will need to be pretty loose to pass through, and your layer of ink will be much thinner.
any mesh count higher than 230 should only be used if you are trying to print SUPER detail or SUPER photographically. My opinion is to not bother screen printing at all if its not going to look hand made......
How big do you want to print?
Understanding the 'usable' space on my screen took me the longest time to get. I was dumb.
It is safe to say that you need to subtract 3 inches from the length of each edge of your screen to get the dimensions of your true 'printable' area.
For example, if your screen is 20x18, the largest image you can print is 17x15. DON'T TRY AND GET AWAY WITH PRINTING A LARGER IMAGE. It sucks. You make a mess, the image won't print easily, you'll waste a lot of paper and ink, and you'll just have to make a new stencil or find a bigger screen. It is a waste of time.