Transparency

[Stuart Thiessen]

I just got introduced to Seashore, so I'm new to it. I am often
creating transparent images (mostly PNG, but sometimes GIF). I cannot
figure out how I am to do this in SeaShore?

Thanks,

Stuart

[i.aten...@gmail.com]

What you're looking for is the Alpha Channel.
The alpha channel is basically an opacity mask, which says which parts
of an image are opaque, and how much.

The alpha channel in seashore is enabled on a per-layer basis. If it
is enabled, then that layer can have transparent bits in it, if
disabled, then the whole layer will be opaque.
To enable/disable it, select the relevant layer in the layer options
box, and select the relevant item in the Layers menu.
Once enabled, deleting selections from the layer will revert it to
transparency, rather than your background colour. If you want finer
controls over the opacity, then select alpha from the Channels drop-
down in the layer options box. you will then see the alpha mask in
greyscale. White is completely opaque, black is completely
transparent, grays are in-between.

if you want to start with a completely transparent image, then check
the box in the new image dialog.

one thing to note: seashore doesn't currently support transparencies
in gifs. this is because it's a bit of a hack. gifs only support
completely transparent/opaque states, and it does it by assigning one
of it's 256 colours to be a 'transparent' colour.
pngs have the full graded transparency that alpha channels allow, so
are much better :)
This is one of many reasons why IE<7 sucks so much...

if you want more detail, i'd recommend a read through the manual (from
the help menu). Honestly, it's actually really good!

hope that helps