There are literally hundreds of easels on the market that are great for dragging around the countryside, but there are a couple of things you will need to consider before spending your cash.
A portable easel could be useless if you choose poorly. After all, it's not portable if it's so annoying that it's dumped in the back corner of the shed, and not touched for 9 years. While not a life threatening decision, choose wisely. It can save some pain.
Your needs are probably the best place to start a search for the perfect portable easel. What do you want to do?
Are you expecting to trek for days into the mountains to paint the lesser spotted dust mouse?
Maybe you are hoping to stop along a quiet road some where and travel only a short distance from your car.
Alternatively, you may be planning to use your portable easel indoors while attending a class or workshop.
Each of these scenarios will help you refine your search.
Any plans to travel any distance will make a good choice important. Probably the further you have to carry it the more important.
Weight is definitely a consideration. So is the shape and size it becomes when folded for carrying.
Something else to consider is, how is it carried? Straps? Handle? Check these for comfort and durability.
The lightest object can become a giant pain if you have to carry it a long way with a broken strap or handle.
You can be sure to utter words you never even knew you knew, if you are carrying an easel that will not fold down to a sleek and small shape. It will catch on every stick or twig you pass. When every second one of them has snapped back and hit you on the bridge of the nose, a poor choice will result in the portable easel becoming truly portable - as it disappears down a ravine to the echoes of your displeasure.
An easel which doubles as a paint box that carries just about everything is a great idea. Make sure the previous attributes are considered. It will make carrying it controllable, especially if it allows you to have a hand free (to protect your nose!).
You will need something that is easily adjustable to allow for uneven terrain. It is surprising how quickly your back will hurt if your posture is compromised by a tilted easel.
Something else that is a must to think about - how is it secured?
It is one thing to throw an annoying easel into a crater. It is another experience entirely when the masterpiece you have worked on for 7 hours disappears into the crater attached to the easel. Removing dust, twigs, and the still warm body of the lesser spotted dust mouse from a partially dry painting is not fun.
A gust of wind has broken many people. You need to find a way of attaching your easel to the ground. A great idea is a couple of tent pegs driven into the ground next to each leg and a wrap or two of strong tape around the peg and leg (the easels, not yours. Ha).
A great idea is the lightweight portable easels that come with white board markers. They fold into an easily manageable size, and are as light as a feather. Cheap too. You will have to set up a system to secure your work to it. Your painting is adequately held at its bottom edge but will need to be held well at the top as well.
This requires a similar set of requirements to the "trekking easel", BUT..... as carrying the easel for long distances through bush is not on the agenda, we can relax about a couple of things.
Our portable easel is less annoying if it does not fold up into a small easily cartable form. It does not have to hold all your paints and equipment, and the handles (or straps) may not be necessary.
Make sure though, that you can secure it to the ground. A friend of mine has a lovely mirror image reproduction of one of his plein air paintings on his car. Complete with dents that fit his easel perfectly. Make sure also that it is able to be adjusted for the fall of uneven ground.
This option, strangely enough, can be harder to make a decision on.
Pinning your easel down is not a big concern (just make sure the air-conditioning is not set to "gale"). Close parking is not always an option. An easel that includes compartments may be a good idea.
You probably will not be traversing large tracts of jungle to get to your preferred spot to paint. Your easel does not have to be completely collapsible. Just know that as annoying as being smacked on the nose by branches is, it is not as bad as being smacked on the nose by the bikie whose Harley you just scraped. Being foldable is still a good idea.
Also being inside, you may feel safer to paint larger paintings. Make sure that your portable easel is still robust enough to hold a decent sized piece.
Something else to consider is - how much room does it take up when extended? Painting indoors can mean other people. Clumsy people. Having a leg of your easel kicked when you are in the zone is traumatising. Lots of bad words.
Hopefully the ground in your studio or other indoor space is level. Adjustable legs may not be needed. I'd get them anyway if possible. It gives you the option to go outdoors if the mood takes.
As you can see there are some painful repercussions to making a dodgy choice in your portable easel.
Hopefully I have alerted you to some of the pitfalls and considerations.
If you want to save some pain, some of this advice will be useful.