This small brush washing jar is made by the same company that makes the Guerrilla Painter pochade boxes.
Despite the marketing claiming that this jar is something special, it’s nothing but a plastic PET (polyethylene terephthalate) jar with a cap with a standard cardboard cap liner coated with foil on the side that faces away from the cap.
Your standard bottled-water bottle is made from PET, so it’s pretty common and pretty cheap. You can buy PET jars with caps on the internet for only about fifty cents each. What is special about this jar is that it’s slightly taller than 1 3/8″ which is exactly the amount of space in an 8 x 10″ Guerrilla Painter box, and I presume that all of the company’s other boxes have at least the same amount of space so that this jar fits in all of their boxes.
The cap liner separated from the cap after only one day of using the jar. Whatever glue was used was really soft and not very sticky and just scraped right off. I needed to use some epoxy to glue the cap liner back onto the cap. Very disappointing quality in a jar that costs $15 (what I paid for it online at Cheap Joe’s Art Stuff).
The jar also comes with a stainless steel insert that’s designed so that you can rub the bristles of the brush against something which isn’t the bottom of the jar. Now this is a really great feature in a studio brush cleaning jar. I have one of those Silicoil jars in which I’ve been using the same mineral spirits (I recommend Gamsol) for a year. The pigments settle to the bottom but your brush never goes down to the bottom because of the coil, so you can keep using the same mineral spirits for a really long time and never have to clean your jar. But this is not going to work for a travel jar, because when you turn your pochade box sideways and carry it around, the mineral spirits will get all shaken up and the pigments won’t stay at the bottom of the jar. In order to make this jar work, after you finish using it you need to pour the mineral spirits into another container where the pigments can settle to the bottom.
This jar’s wide mouth makes it very difficult to pour the mineral spirits out without it dribbling down the sides of the jar and making a mess. You definitely need a funnel.
You definitely don’t need to buy this jar if you already have a jar with a cap liner that fits in your pochade box. But I doubt you have a jar this size. It’s a pretty unusual size. I was unable to find anything at Amazon. It’s lot easier to spend $15 to buy this jar than to try to find another jar that works.
By the way, mineral spirits are a very weak solvent and can be safely stored in any plastic container except for those made from LDPE (low-density polyethylene). Make sure the recycling symbol on the plastic container doesn’t have a #4 which means it’s made from LDPE.