Is it possible to do an ALPHA MATTE in photoshop?

[Jeff Cochran]

Yes it is.

Go to the windows pull down menu > Channels.

Copy and paste the line art drawing into a new channel. Now when you save this file that channel will act as an Alpha

Jeff Cochran

https://www.jeffcochrandigitalartist.com/

[Daniel Haskett]

Wicked thanks for your help! So its not possible to see the affect it has until you have saved it?

thanks
dan

[Jeff Cochran]

Here’s a way to see the effect (Sort of)

Hold down the apple key and click on the channel icon in the channel palette. This will make a selection out of the channel. The marching ants will give you a good idea what will show and what wont. You can also make a layer mask from the selection, that will give you a good idea what it looks like. Otherwise, yeah, you really wont see it until you get it to AE.

Jeff Cochran

https://www.jeffcochrandigitalartist.com/

[Filip Vandueren]

Hi Daniel,

you can also double-click on your background-layer, so it becomes ‘layer 1’.
The background layer cannot have transparancy, but layer 1 can.

Now select your Alpha Channel like before, so you have the marching ants.
Then hit the little “add layer mask” button in the layers-palette.
You should have transparancy now. and You can safely delete the fourth channel.

Since After Effects understands PSD files pretty well, it will see this transparancy as an alpha channel even though it is not explixilty a 4th channel.