So how to use the Illustrator scribble effect for doodles, sketches, scratchy effects etc and use with type and paths etc. How to create amazing designs using the feature in the effects menu. Select any path such as a rectangle or text or circle or path that you have created and go to the effects menu and select the stylize menu and go to the command at the bottom of the menu
The panel will now appear and you can set the curliness, spacing and other settings. It is probably easier to test out a number of settings by going to the presets (swash, dense, child like etc) at the top of the panel and apply those to see which one you like and then manipulate the various sliders to tweak it. It is odd that there appears to be no way of adding your own presets so if you hit on a great loose sketch style, you have to remake it each and every time. Stroke width does not vary over the selected path, it is a single width all the way. Path overlap is great for extending the doodle lines out of the main area of the path or use the inside setting to keep the lines clearly inside the shape. You can also add some variation to most of the settings. You can also change the angle which can result in a dramatic result. Once you are happy, apply it.
Best way to run through it has to be the settings at the top of the panel, just select one of those. The variation settings are super useful as well as you can add a little randomness into the art - do not ignore the variation settings as you can use it create some wild curliness with your lines and they can go all over the place.
Some of the settings such as stroke width can't have any variation as the design is basically a single stroke
You don't have to have a stroke and you don't have to have a fill when it comes to the selected object or objects as it can work on multiple objects. Select a path with no fill and only a stroke and then apply and you will see the line change based on the current settings. You can create intense lines but also lines that spread out and very loose.
By default, it is added to the fill and stroke. However, you can move it so it is only applied to the fill or the stroke and not both and you can also add it to other entries. The appearance panel which can be found via the window menu. It is the master control for all these types of applied actions and you can also combine the fill / stroke and the hand drawn / doodles with transforms / blurs etc. You can update the settings at any point
With the panel open, you will see the result of the applied setting, select it and drag it to either the fill or the stroke. Also go to the right side menu of the appearance panel and select add a fill or stroke and then you can add the same or a different settings / end result to that fill or stroke as well as combining it with other actions such as blur or zigzag or transform etc. Adding a blur to one of the sketchy designs as well as a transform. You can also use the panel to select an entry and then delete it.
You can also go to the graphic styles panel (also in the window menu) and go to the right side menu and create a new graphic style and all the fills and strokes as well as the various actions etc will be added into a single graphic style which can be applied at any point to paths as well as type and other objects. This is saved with the document and is not a permanent feature so if you want to see the style later, save it to a library and use it via a library of styles.
Select some type or create some type and go to the styles panel and apply or apply the menu command to add a hand drawn / sketchy / loose etc result. All the characters will be modified in the same way. You may wish to expand the type before applying it so go to the object menu and expand and then also ungroup the result and then use it with the individual objects as you will then be able to change the settings for different letters so the A or B could have a loose sketch and the B could have very rapid wavy result. You can then transform the design and increase the size or decrease it and rotate the letters etc and those subtle changes will also have a result with the applied sketch.
The one trouble with this effect is reliant on the size of the artwork. If you re-size the artwork, you will notice the lines will also change so may have to go to the spacing, stroke width etc fields in the panel and tweak them to get a comparable result. Changing the angle of the design should not change the line's direction but you may want it to point in a different direction so change that in the angle field at the top of the panel.
Once you have finished with all the settings then you can also expand the appearance (it is a live option so it needs to be expanded in that way) and expand the fill / stroke via the object menu. You can then manipulate the artwork as required. You can then add additional fills and strokes to the artwork and if you wish you can then also apply the same action to those lines but as the sketchy lines are quite complex (and a lot of points), you may find additional settings added on top of those doesn't always work well and the result is not always as expected as well as sometimes slow to process. I would not recommend more than another application of the sketch / doodles etc as three or four will be very very slow to process and probably crash the application.
You can also use the artwork within the repeat setting where you can create a radial (or grid or mirror) and it is still live and you can tweak the paths in all kinds of ways to create all kinds of wonderful artwork. You can also use the repeat command 'grid' and 'mirror' also in combo with the radial.
You can also use the pattern command and make pattern via the object menu with the path attached though it should be noted that it is no longer live when you are creating patterns nor is it saved as a live swatch. https://youtu.be/oEc849lPYpQ
The artwork can be saved as a symbol and that design then can be applied to the art board with the sprayer tool and sized, stained, spun and more
You can change it any point by going to the appearance panel and double clicking the entry and you can then tweak the settings such as change the curliness or the stroke or path overlap etc
You can also export the work to Photoshop so you can add a sketchy design or two to that application or other parts of the Creative Cloud by using the CC libraries or just copy and paste.