Millinery Blocking Pins – Best practice guide

Blocking pins and a metal thimble

Millinery blocking pins? Why not just blocking pins? Many craftspeople block their work with pins from knitters to lacemakers, so it’s not an exclusive millinery term. I’m only going to be talking about what milliners can buy and often use.

What are blocking pins?

Blocking, in millinery, is the process of shaping materials over a wooden hat block.  Sometimes the material is flat, and we are giving it a 3D shape, and sometimes, we use a hood or hatbody, which is already partially shaped but needs further work. To achieve the desired shape, the fabric needs to be held close against the wooden block, which is where blocking pins come in.


What types of millinery blocking pins are there?

There are many types of pins milliners can buy and use. Below are the four varieties I cover here. However, most other types of pin closely resemble these four, and you can substitute others that are similar. However, just because a pin looks the same doesn’t mean they are. I bought pins that were the same size and shape as the blocking pins I sell now, but they bent very easily. So my recommendation is that you buy them from me because I have done all that work for you and made sure I would use them before giving any product the ‘ok’. Many are available in stationery shops or as dressmaking accessories, and the thumb tacks are the same as push pins or map pins in most ways.

Pin TypeAdvantagesDisadvantagesThicknessLength
Steel Blocking Pins - tableSteel Blocking PinsSturdy, thin enough but don't bend easily
Requires practice to use proficiently, only available in specialty stores
Thumb TacksThumb Tacks or Drawing PinsEasy to find and put in
Leaves large holes, can break in the block, hard to place close together
Red Blocking PinsRed Blocking PinsThin, easy to put in the block
Only available in specialty stores, bend easily, can bleed colour
Lace PinsLace Blocking PinsThinToo short to block by hand

Why is blocking pin thickness important?

As you can see in the table above, the thickness of blocking pins varies quite a bit. There are two factors you need to consider about thickness. One is how big a hole does the pin leave in the block? The larger the hole, the more damage to the block every time you put a pin in it. Don’t worry; your block won’t fall apart if you use drawing pins once, but if you regularly use the block, it will wear out faster than using thinner pins. Secondly, the thinner the pin, the easier it is to bend. Bending pins when you block is a pain in the neck; next time you use the pin, it’s often unusable. If the pin bends easily, it will bend before being pushed into the wood, and may not hold at all.

What about pin length?

If you disregard the inserting of blocking pins, their length is not very important. As long as it can go in far enough and hold your material in place, then you don’t have a problem. Thumbtacks tend to be just long enough, but I find the red pins on the short side. Now, if we look at inserting pins, we come to a problem. When you use steel blocking pins like the ones I do, they have to be long enough to extend out from your fingers when you hold them so that you can push the pin into the wood. My fingers are about 16mm where I grip the pin, and I need about 3-4mm to push in, so the absolute minimum pin length is around 20mm. Pins under that length are useless for blocking unless you are using a pin pusher, so beware of the length when you buy.  

So, what are the best millinery blocking pins?

Hands down, steel blocking pins win on so many levels. That’s why I use them exclusively and sell them at Millinery Hub. Of course, that’s my opinion, albeit backed by experience and trial, but I can see why others may use different pins. In the end, it’s about what’s right for you and right for the project at hand.

Pin Pushers

There are a couple of types of pin pushers, but both are tools that help you insert blocking pins. One will help with thumbtacks and the other the steel pins. The one for thumbtacks looks like a doorknob with a metal shaft. It has a concave end that fits the round metal thumbtacks in and you can push on it. The other type is for the steel pins. It looks like a screwdriver without a blade, but it has a hollow tip (usually magnetic) where you insert the pin. When you push it against the work, the pin is inserted.

Pin pushers have the disadvantage of requiring two hands to use (to loead the pin) and so you have to keep taking your blocking hand off the material. For this reason, I recommend using one only if you can’t block without it.

How to use millinery blocking pins

Using thumbtacks and red blocking pins is fairly self explanatory and doesn’t require much skill. However, mastering the use of the steel blocking pins is a little trickier. It’s much easier to watch it than for me to write it down here. So if you want to lean how, I suggest you watch the video I prepared on blocking pins. As with all skills, it requires practice to get proficient, and I suggest you do as much practice on an easy project (soft block) as you can until you can put pins in without hesitation. It’s not an easy skill to learn, but you will thank yourself when you do.

Other considerations

Most millinery blocking pins are made out of steel (not stainless steel). Therefore, like sewing pins and needles, they can rust. This is especially relevant in millinery because we use water when blocking most materials. It doesn’t tend to be a problem with a normal workflow, but if you leave blocking pins in a block for an extended period (say a week), you may find they rust around where the material is. So if you wish to leave your work on the block to protect the shape, I’d remove the pins once the work is dry.

Once pins start to rust they should be discarded as rust begets more rust. New pins are cheaper than a ruined hat. You will need to be more vigilant if you use PVA as a stiffener as this can encorrage rust.