Using a single layer VS. multiple layers when drawing a portrait?

[southwestform]

I want to place a portrait into AI and create a new layer and use the Pen tool and the Pencil tool to draw over the portrait. When doing this type of work in AI, does it make sense to use lots of layers or will a single drawing layer be OK? In Photoshop I might use separate layers for healing and cloning in different parts of an image so I can use different layer opacities for each layer. Are there any similar reasons in AI to put each facial shape, ex: eye on a separate layer?

Thanks.

[Monika Gause]

It makes sense to put your template onto its own layer. Make it a template layer, so a pixel image will stay visible when you draw in outline mode.

Then create a layer for drawing your portrait.

It might make sense to create additional layers for details of the drawing.

But layers aren't crucial for editability as they are in Photoshop.

It's good practice to have layers in order to structure your AI file in order to hide something easier or select it.

Opacity in Illustrator can be set for each single path or even for the fill and the stroke differently.

[JETalmage · Accepted solution]

There is a widespread confusion among Photoshop users about "Layers" when they start using vector drawing programs like Illustrator, because although they are named the same, they are fundamentally different constructs.

Programs like Illustrator are object-based. Every single path, text object, or raster image in the file is, in fact a separate object. The whole file is a "stack" of independent objects, stacked in sequential order front to back, whether they overlap or not. A Layer is just a logical reference to a range of objects that are adjacent to each other in that Z stacking order; like merely putting brackets or parentheses around a few sequential words in a sentence.

That's really all a Layer is in this kind of program. Logically, it's the same thing as a Group, except that selection behaviors are different. A Group is also nothing but a range of objects which are contiguous in the object stack. But the Group construct is used to act like one object when selected or moved on the page, whereas objects in a Layer are still individually selectable on the page. (The contents of a Layer, can also be selected all at once, but in the Layers palette, not on the page.)

So you are always actually working with many individual "layers" (in the sense of layers in a raster imaging program) whether you deliberately assign a range of objects to any Layers or not.

It follows that you can use either Layers or Groups (or both) to organize the objects on your page in whatever fashion works for your particular purpose or preference. That's why there is no one correct answer to your question.

In the early days of these programs, the Layers palette did not list every individual object; it just listed the names of user-defined Layers. That was intuitive in the original metaphorical sense of a physical "layer" (like an overlay sheet on a paste-up). But later, software vendors started listing all the individual objects in the layers palette and depicting user-assigned layers like folders in a list of files. In doing so, that kind of broke the original metaphor and created a lot of unnecessary confusion among beginners largely because they still insist on calling it a "Layers" palette.

It isn't. It's just an objects list in which objects can be organized into logical "folders." When the software publishers started listing all the individual objects in the so-called Layers palette, they should have changed its name to "Objects"  or "Objects List". That would have been more intuitive, especially to newcomers.

Many longtime illustrators (myself included) typically do not create more than a few Layers, even in elaborate drawings, and make more use of Groups. Many newer users do the opposite (often assuming it "best practice" because they confuse the construct with Layers in programs like Photoshop). But you can work either way. Neither is necessarily best practice in all situations.

JET

[Doug A Roberts]

layers, for me, are useful when i think i will need to be continuously making some aspects of an illustration visible or not visible. so i might have line work, base colours, and shading (gradient objects etc.) on separate layers because i'll be turning them on or off as i draw to get a look at other bits and want quick access.