OUGD504: Creative suite workshop 2

Photoshop

You can always tell the colour mode on photoshop by looking at the bar at the top of an image (or the tab). The colour mode will be in the brackets.

To change the colour mode you can go into image > mode.

There are colours that you can produce in the RGB mode that can't be reproduced with CMYK inks. Colour gamut is a range of reproducible colours. The RGB colour gamut is larger than the CMYK colour gamut.

RGB is photoshop's default colour mode. Everything you open will be RGB. Make sure if you're working for print, change to CMYK. (Colours can change drastically)

We are going to work with three images.

Here is the first:

There is an option called gamut warning in the view menu, and it highlights colours which are out of the printing range.

Changing the saturation (vividness) can effect the colours.

You could also add an adjustment layer, add a mask and select the parts which need changing. So rather making adjustment of the whole image you can just make adjustments of the selected parts.

When you choose proof colours it allows you to work in RGB mode, but what we see on screen is how the image will look when we convert it to CMYK.

Proof set up is where you can change what colour mode the proof colours works with.

Official Adobe photoshop - printing images to a commercial printing press:

"Work in RGB mode until you finish editing your image. Then convert the image to CMYK mode and make any additional color and tonal adjustments. Especially check the highlights and shadows of the image. Use Levels, Curves, or Hue/Saturation adjustment layers to make corrections. These adjustments should be very minor. Flatten the file if necessary, then send the CMYK file to the professional printer."

Source: http://help.adobe.com/en_US/photoshop/cs/using/WSfd1234e1c4b69f30ea53e41001031ab64-779da.html#WSfd1234e1c4b69f30ea53e41001031ab64-779ca

Working with swatches:

First of all to get a clear swatch pallet makes things a lot easier, and makes the colours clearer to work with. Unfortunately on photoshop you have to deleted the default colours one by one. So if you deleted all the swatches and leave one colour. Save this as a swatch, so that next time you can load this up and it will load this one colour and delete all the default ones. This is an easy way of deleting all the coluors. Once its been done once it doesnt have to be done again.

When choosing the colour, in the colour box by the side of the bigger colour box you can see an exclamation triangle and a cube.. The triangle means the colour cant be printed a gamut warning, and the cube is for web.

By clicking the exclamation mark it changes the colour to the closest colour which is printable.

After selecting a preferred colour, if you click in the swatch menu it will add this to to the swatch pallets.

Using spot colours in photoshop:

Spot colours are usually specified by clients, it can be cheaper to print in spot colours.

If you go into the colour picker and click colour libraries it opens up the options to pick spot colours.

You can find your pantone colour by simply typing in the reference number.

To make sure the colour can be reproduced when printing, you need to take a reference number.

A photoshop document can only support one colour mode. So RGB or CMYK

Illustrator can support more than one colour modes. So you can have RGB working with CMYK.

Duo tone images

When working with duo tone you have to start with an image in greyscale. You then can go to image > duo tone

In duo tone it starts to consider inks, to change the ink click the colour square. As you can see the type is monotone, which means we're working with one colour

The square on the left with the line through it is a duo turn curve.

An exact mapping of your new ink to your old ink. You can use it to see how the colour maps to the old ink.

You can adjust the brightness and contrast of your printed image by using the duo tone curve.

Duo tone and mono tones are editable.

If you select the duo tone option, you can choose a second ink

You can also work with Tritones and Quad tones, but bare in mind that these use more inks when printing. This can get expensive.

Save the file as the photoshop format to keep the same colours on the image when printing.

An alternative way of working with spot colours

We need to understand the channels

The channels reflect the colour mode of the image. As we are in greyscale our image has one channel.

Viewing different channels on a CMYK image:

If you go into the options you can create a spot channel, you can choose what colour you desire. Again you can open the colour picker and choose a pantone colour of your choice.

All channels are black and white images that define how the colour is going to be applied.

You can then apply this colour to the greyscale image by using the paintbrush.