Re: Can I do this in Photoshop?

In article <Jnd4e.14747$>,
Lurkis Jerkis wrote:

Using a blending option like hard light, screen, or overlay should do the trick. Set your background color to the color of the media and toy with these until you find the on that seems to approximate the effect.

I’m afraid I’ve already tried that – no joy 🙁

For example – a black area on the image should stay black – a white area on the image should become the media colour. None of the blending options produces the right effect.

Could I do something with alpha channels?

Mark

This is hard to answer without seeing your art. But you could try alpha channels (mask). Here is how:

Select all on a layer and copy. (if all you have is a background layer dupe it and work in the new layer)

Select Layer>Add Layer Mask>Reveal All

Option + Click (Mac) or Alt + click (PC) on the mask icon in the Layers panel. (this opens the mask (channel) editing mode.)

Paste

Click on the color icon in the layer panel.

What this should give you is a mask where a solid color is opaque and a transparent color is gray. Place your t-shirt color underneath and you will get an approximation of printing.

Let me know if you need more help.

dp

Mark Wheadon wrote:

In article <Jnd4e.14747$>,
Lurkis Jerkis wrote:

Using a blending option like hard light, screen, or overlay should do the trick. Set your background color to the color of the media and toy with these until you find the on that seems to approximate the effect.

I’m afraid I’ve already tried that – no joy 🙁

For example – a black area on the image should stay black – a white area on the image should become the media colour. None of the blending options produces the right effect.

Could I do something with alpha channels?

Mark

In article , (Mark Wheadon)
wrote:

In article <Jnd4e.14747$>,
Lurkis Jerkis wrote:

Using a blending option like hard light, screen, or overlay should do the trick. Set your background color to the color of the media and toy with these until you find the on that seems to approximate the effect.

I’m afraid I’ve already tried that – no joy 🙁

For example – a black area on the image should stay black – a white area on the image should become the media colour. None of the blending options produces the right effect.

Multiply mode should work just as you describe. If that’s one of the ones you’ve tried, please give details of what went wrong, i.e. what colours were involved.

—
Odysseus

In article <80bd3$425181d3$4528b9dc$>, bogus <bogus> wrote:

Let me know if you need more help.

Thanks – the trouble with that is that anything non-white is completely opaque. What I’m trying to simulate is the laying down of ink. So a solid primary colour is completely opaque (and hence doesn’t transmit any of the background media colour) – so black or say bright blue on red cloth will come out unmolested. But, say, a light blue is done by laying down less ink and allowing the white paper to show through – so when printing on to the same red cloth, a light blue will end up as a mix of the red of the cloth and the blue of the ink laid down.

Does that make sense?

Thanks,

Mark

In article ,
Odysseus wrote:

Multiply mode should work just as you describe. If that’s one of the ones you’ve tried, please give details of what went wrong, i.e. what colours were involved.

Hi, you’re right for my (bad!) example – multiply works for black and white. But I’m trying to simulate the laying down of colour ink onto the media. So, for example, printing on to pink cloth will result in fully saturated primary colours looking as one would expect, but less saturated colours will allow the pink cloth to shine through – the less saturated the colour (by that I mean the less ink (or, if you like, the more white) there is in the colour) – the more the background colour shines through.

This is becuase the printer works on the assumption that it’s printing on to white media – so what I’m trying to simulate somehow in photoshop is replacing any "whiteness" in a given pixel with the same level of background colour…?

Thanks,

Mark

"Mark Wheadon" wrote in message

This is becuase the printer works on the assumption that it’s printing on to white media – so what I’m trying to simulate somehow in photoshop is replacing any "whiteness" in a given pixel with the same level of background colour…?

Try the Screen mode in the layer then adjust transparency or fill.

"Mark Wheadon" wrote in message

In article <80bd3$425181d3$4528b9dc$>, bogus <bogus> wrote:

Let me know if you need more help.

Thanks – the trouble with that is that anything non-white is completely opaque. What I’m trying to simulate is the laying down of ink. So a solid primary colour is completely opaque (and hence doesn’t transmit any of the background media colour) – so black or say bright blue on red cloth will come out unmolested. But, say, a light blue is done by laying down less ink and allowing the white paper to show through – so when printing on to the same red cloth, a light blue will end up as a mix of the red of the cloth and the blue of the ink laid down.

Does that make sense?

Yes it makes sense but it is not quite right. In your original post you said that light blue over red would produce cyan but this can not happen. The result will be a purplish colour slightly darker than the original red. A really intense blue pigment might cover the red but your printer will be using a mixture of cyan and magenta to achieve this.

But what you asked is how to set up photoshop so that you can replicate the effect of printing on a coloured background. I suspect that ‘Multiply’ mode is probably closest. If the effect doesn’t look like you expect then I think you are going to be disappointed.

John

(Mark Wheadon) wrote:

In article ,
Odysseus wrote:

Multiply mode should work just as you describe. If that’s one of the ones you’ve tried, please give details of what went wrong, i.e. what colours were involved.

Hi, you’re right for my (bad!) example – multiply works for black and white. But I’m trying to simulate the laying down of colour ink onto the media. So, for example, printing on to pink cloth will result in fully saturated primary colours looking as one would expect, but less saturated colours will allow the pink cloth to shine through – the less saturated the colour (by that I mean the less ink (or, if you like, the more white) there is in the colour) – the more the background colour shines through.
This is becuase the printer works on the assumption that it’s printing on to white media – so what I’m trying to simulate somehow in photoshop is replacing any "whiteness" in a given pixel with the same level of background colour…?

Try the following:
Set the background layer of an image to the color of the cloth you will print on. Put your picture on top of this background. Select the luminosity of your picture (Ctrl-click on the RGB channel for the selection), invert the selection and use the selection as a layer mask. Now the picture is transparent in proportion to its luminosity. This might give a result similar to the effect you see when printing on colored media.

HTH, Peter