Raising my screenprinting game: three things that have helped me hone my craft

In the last year a few things have really helped me to hone my craft. They are as follows:

Colour sensor

I used to struggle with mixing inks exactly how I wanted them. Especially yellows, which would look right to me but when printed looked way too vibrant. Colour proofing helped but I was wasting lots of time.

So, I got a little colour sensor (mine is a Nix Mini 3). It has transformed my ability to get colours right. 

The process is pretty simple. I use the computer to choose colours for my print. Even if I'm working with natural media I end up with the artwork on a computer. I then sample the colours on the computer, get the target CMYK values and write them down in my notebook.

I pick out tubs of mixed ink which are closest to what I want and adjust them by eye to match an image on my phone of my illustration. Then I paint each of the roughly mixed colours onto a sheet of paper as a swatch.

Now the colour sensor comes in. Open the app on the phone, sample each of the colours in CMYK and write the values below the swatches.

It's a simple task of comparing the values of the swatches with the target values in my notebook. I can instantly see if a colour needs more or less cyan, magenta or yellow. If all values need to come down then white can be added.

Of course you can't merely mix colours using a sensor. You need to use your eye. Once I've got the mixed colours close to the target values I will stop and print a colour proof. This is the point at which I will judge by eye if it looks like I wanted it and make subtle adjustments accordingly.

It's not a perfect system; you can't measure things like transparency of inks, so if you have a lot of overlapping transparent colours then you need to judge how much transparency you need as well as getting the colour right. 

Vacuum Bed

The second thing which has helped me enormously to improve my printmaking is my vacuum bed.

I decided to build myself a vacuum table to fix a number of issues I was having. For example, without a vacuum table each sheet of paper would have to be taped down with masking tape. Even then, the paper would sometimes lift up with the screen. Not necessarily a problem in itself but it could result in a ghosted image on the back of the screen if the paper moved and would require printing onto sheets of scrap paper to remove the ghosted ink from the screen. 

The other problem I was getting was a tide mark on large areas of colour. It would result in a noticeable variation in colour where the paper had lifted with the screen and then come off.

Not having room enough for a proper screenprinting table, I constructed a vacuum bed.

I purchased a large sheet of 3mm thick aluminium, about 900mm square. I then drilled holes all over it, 1 inch apart.

I managed to do this without breaking the drill bit though it did take a while! Then I simply constructed sides for it using 20mm wide wood and put a back on using a sheet of plywood. The whole thing was screwed together. Finally, I chiselled out a hole in the side to fit the nozzle from our vacuum cleaner.

With the vacuum cleaner plugged in to the hole, the vacuum bed works incredibly well. It is important to mask off all the spare areas of the vacuum bed with newspaper so that the vacuum works well on the paper you are printing on.

It keeps the sheet of paper I am printing on stuck to the table and in one place. No longer does it lift up or move around or create tide marks.

Registration

Finally, I have improved my registration technique to the point where every print is practically perfectly registered which has allowed me to do more challenging prints of multiple colours with fine detail.

So, I still use a sheet of acetate, which is large enough to cover the print area and the registration marks of the screen. 

I decided to go back to registration marks because I was getting too many errors with aligning everything by eye. The problem is that as you progress through the print, the alignment errors can be compounded as you try to align with layers that are progressively further out of alignment.

If I use registration marks and trust those, there are no compound errors. One layer might be slightly in the wrong place, but it doesn't mean the rest of the layers will be.

I also tape down the whole edge of one side of the acetate (in my case the left hand edge) and use masking tape at three places on the other side. The aim is to get the sheet of acetate as tight and flat as possible.

Even though it is slower, I now register every print by eye and the results are worth it!

These three changes, together, have enabled me to really hone my screenprinting craft to the point where I feel like I could tackle anything and also have a good success rate.